EDS 103 Module 3.3 Information Processing Theories- … · Module!3.3!COGNITIVE!THEORIES!!!!! "Experiential,Learning,Theories"!! Site:! University!of!the!Philippines!Open!University:!!

10/4/2015 Module 3.3 COGNITIVE THEORIES

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Module 3.3 COGNITIVE THEORIES

"Experiential Learning Theories" Site: University of the Philippines Open University: Course: EDS_103_1T_2015-‐16-‐Theories of Learning Book: Module 3.3 COGNITIVE THEORIES Printed by: Reyes Maria Joanna Rose Date: Sunday, 4 October 2015, 9:45 AM





Table of contents

1. INTRODUCTION; Objectives

2. INFORMATION PROCESSING APPROACH

2.1 Resources to study

2.2 Bite-‐size notes

2.3 Study Questions

3 Theory in Action

4 Discussions

5 Suggestions for your eJournal



1 INTRODUCTION; Objectives

-‐What principles underlie information processing theories?

-‐ How important is attention, and how does it affect learning? -‐What are the different memory stores? -‐How are memories made, stored, and retrieved? -‐How may we improve memory storage and retrieval? -‐How is perception explained by information processing theories of learning? -‐How may learning events, in and out of school, be explained in terms of cognitive processes according to the information processing theory? LEARNING OBJECTIVES After studying the four sections of this module, you should be able to:

-‐discuss the basic assumptions that underlie the four major learning theories—behavioral, social, constructivist, and cognitive;

-‐propose theoretically principled explanations for the way students respond to learning events;

-‐use core concepts of learning theories to analyze teaching-‐learning events and predict learning outcomes;

-‐propose theoretically justified approaches to improve pedagogy. INTRODUCTION Towards the late 20th century, the emphasis in psychology began to veer towards the cognitive view. From behavior, the focus gradually shifted to thought processes, with particular interest on memory (Huitt, 2003). The emergence of the cognitive perspectives of learning was partly due to the failure of behaviorism to sufficiently explain complex phenomena, e.g., language learning and problem solving, as well as differential responses of people to a common stimulus. While behaviorists view learning as consequences of responses to stimuli impinged on man, cognitivists view learning as consequences of man’s active attendance to and reorganization of information into meaningful knowledge, coupled with an innate desire to understand the world (Schunk, 2012, 165). The principal concern of proponents of cognitive theories are internal (mental) processes that intervene between stimuli and responses. The outcomes of processing information include remembering, concept-‐formation, reasoning, problem-‐solving, and a host of other complex knowledge or skills.



-‐-‐-‐ Learning is a change in people’s mental structures instead of changes in observable behavior. -‐-‐-‐ In brief, cognitive theory asserts that learning invokes changes in people’s mental structures instead of changes in observable behavior; i.e.,learning is a mental process. KEY ASSUMPTIONS OF COGNITIVE LEARNING THEORY -‐Learners are active seekers and processors of information. They manipulate, monitor and strategize processes applied to information. -‐Prior learning influences how new understanding develops. -‐The capacity to process information gradually progresses, thus allowing learners to increasingly acquire knowledge and skills (Santrock, 2011). MAIN COGNITIVE APPROACHES TO LEARNING

-‐SOCIAL LEARNING– Learning is influenced by the interactions among behavior, environment, and the individual

-‐INFORMATION-‐PROCESSING APPROACH -‐ Attention, memory, thinking, and other cognitive processes characterize how people learn

-‐CONSTRUCTIVIST APPROACH -‐ the development of knowledge and understanding involves the process of construction

-‐-‐-‐-‐-‐Cognitive constructivist approach – emphasizes cognition/ mental processes. -‐-‐-‐-‐-‐Social constructivist approach –emphasizes the collaborative and other social processes. (Holzman, in Santrock 2011, p. 218)



2 INFORMATION PROCESSING APPROACH

In this module, we shall focus our attention on the information processing approach to learning. Information processing theories put an emphasis on the structures and functions of mental processes, specifically memory. INFORMATION PROCESSING THEORIES -‐structure of mental processes/ memory -‐functions of mental processes/ memory -‐ COGNITIVE RESOURCES (capacity and speed and cognitive skills) = determinants of MEMORY = biology and experience contribute to growth in cognitive resources (Bjorklund, 2011). The theory assumes that human learning is analogous to computer processing; i.e., information is received, stored in memory, and retrieved as needed. As individuals gain maturity and experience, both the capacity and speed of information processing capabilities grow. In information-‐processing theory, capacity and speed comprise cognitive resources, which are posited to be strong determinants of memory and other cognitive skills (Santrock, 2011, p. 255).

Cognition -‐ thought Memory -‐ the storage and retrieval of information (SOURCE: Huitt, 2003) -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ "Both biology and experience contribute to growth in cognitive resources (Bjorklund, 2011). Think about how much faster you can process information in your native language than in a second language. [Changes] in the brain … provide a biological foundation for increased cognitive resources (Zelazo & Lee, 2011). As children grow and mature, important biological developments occur both in brain structures, such as changes in the frontal lobes, and at the level of neurons, such as the blooming and pruning of connections between neurons that produces fewer but stronger connections (Nelson, 2011). Also… myelination (the process that covers the axon with a myelin sheath) increases the speed of electrical impulses in the brain. Myelination continues at least through adolescence (Paus, 2009)"

-‐-‐Excerpt from Santrock, 2011, p. 255 Stage theory (Atkinson and Shriffin), levels-‐of-‐processing theory (Craik and Lockhart), parallel-‐distributed processing model, and connectionism (RumelHart and McClellans) are among the widely accepted information processing models in cognitive psychology.



2.1 Resources to study STUDY: (REFER TO PAGE 15 FOR THE NOTES) (The list includes very basic resources for beginners.)

1. Cognitive Psychology (MacLeod, 2007). 2. Information Processing Theory (Schraw & McCrudden, 2013/ Education.com) 3. Types of Memory; 4. Memory Processes (Mastin, 2010)

5. Chapter 6: Memory (Dewey) Part Two: Different Types of Memory: 6. The Atkinson-‐Shiffrin Model 7. Criticisms of the Three-‐Box Model 8. Iconic Memory 9. Echoic Memory 10. Working Memory 11. Rehearsal 12. The Magical Number Seven plus or minus Two 13. Varieties of Secondary Memory 14. Declarative vs. Procedural Memory 15. Implicit vs Explicit Memory 16. Priming 17. Summary: Different Types of Memory 18. An Overview of Memory and How it Works (Cherry/ about.com) 19. What Is Short-‐Term Memory? 20. What Is Long-‐Term Memory? 21. What is Episodic Memory? 22. What Is Procedural Memory? 23. Memory Retrieval: Retrieving Information from Memory 24. What Is Clustering? 25. Explanations for Forgetting: Reasons Why We Forget 26. Information processing and memory: Theory and applications (Lutz & Huitt, 2003) 27. Information Processing (Anders, 2008) 28. Levels of Processing (Craik & Lockhart) 29. Information Processing Theory (George A Miller) 30. Top-‐Down VS Bottom-‐Up Processing (Sincero) 31. The Information Processing Approach to Cognition (Huitt, 2003) 32. Information Processing Theories -‐ Section III (Brogan, 2009) 33. Primacy/Recency Effect (Sousa)



Demonstrating the Primacy Effect

Video: (Cherry)



2.2 Bite-‐size notes EXECUTIVE (CONTROL) PROCESSES INVOLVED IN THE MECHANISMS OF COGNITIVE CHANGE

-‐Attention: focusing mental resources

-‐Perception: pattern recognition to make meaning from stimuli/ environmental inputs; requires inputs to be held in sensory register and compared with prior knowledge from LTM. -‐Rehearsal: retaining information through repetition -‐Encoding (LTM): making connections to create meaningful context in long-‐term memory (LTM) to -‐Forgetting: failure to recall – debatable if merely due to a lack of good retrieval cues

-‐-‐Complex cognition -‐ imaging (visually representing information), decision-‐making, metacognition, self-‐regulation, and motivational strategies, most of which are discussed in greater depth in the chapter on complex cognition.

MEMORY “Memory is the retention of information over time… Memory anchors the self in continuity. Without memory you would not be able to connect what happened to you yesterday with what is going on in your life at present. Today educational psychologists emphasize that it is important to view memory not in terms of how children add something to their memory but rather how they actively construct their memory (Ornstein & Light, 2010; Ornstein & others, 2010).”

(Source: Santrock, 2011, p. 263) TYPES OF MEMORY STORES

-‐Sensory memory

-‐Working memory

-‐ Long-‐term memory MAJOR COMPONENTS OF INFORMATION PROCESSING

-‐attention

-‐perception -‐short-‐term (working) memory -‐ long-‐term memory



Source: Santrock, 2011, p. 263

Episodic and semantic memories compared, at a glance

ATTENTION Attention strongly determines how well information is processed cognitively. An important aspect about attention that we should take note of is the aspect of limited capacity. Hence, individuals have to allocate this limited resource. TYPES OF ALLOCATION OF ATTENTION

-‐Selective attention – selective focus on a specific, relevant aspect of environmental stimuli, ignoring the irrelevant stimuli (e.g., listen to one speaker in midst of several people talking)

-‐Divided attention – paying attention to more than one event simultaneously, multitasking (e.g., listening to music and studying a lesson)

-‐Sustained attention vigilance; maintaining focus over a sustained period of time, a problem characterizing children with ADHD -‐Executive attention –deployment of attention to effectively engage in cognitive tasks such as planning, allocating attention to goals, error detection and compensation, monitoring progress.

Source: Santrock, 2011, p. 258



2.3 Study Questions

-‐How did the cognitivist perspective evolve from the behaviorist perspective? What pushed its development?

-‐What basic assumptions/general principles underlie information processing theories?

-‐Describe Atkinson and Shiffrin’s stage theory model of memory.

http://en.wikiversity.org/wiki/Invariant_Tasks:_Principles_for_Learning

-‐How does Atkinson and Shiffrin’s model explain mechanisms of change in learning? What are the different memory stores? How are memories made, stored, and retrieved? -‐Compare the duration and capacities of short-‐term and long-‐term memories. -‐ How may we improve memory storage and retrieval? -‐What are some criticisms to the Atkinson-‐Shiffrin model? -‐Briefly compare the different models of information processing: -‐-‐Stage model -‐-‐Dual Coding Theory -‐-‐Schema theory, parallel distributed processing, and connectionist models

-‐Describe how the following operate in information processing: -‐-‐Encoding -‐-‐Structuring and Organizing -‐-‐ Storage and retrieval

-‐Explain the argument that attention is a limited resource. What are its implications for learning?

-‐Which attentional allocations (see list above) are most important for the effortful control that is necessary to effectively engage in complex tasks? Adapted from Santrock, 2011, p. 258

-‐Describe/ Compare the different types of memory.



Source:

http://www.human-‐memory.net/types.html

-‐Why do we fail to remember (store) information (what we have experienced, sensed, or perceived)? Why do fail to recall (retrieve) what we have previously stored in memory?

-‐Define each of the following-‐-‐ attention, chunking, clustering, priming-‐-‐and describe their roles in processing information (in the formation of memory or learning).

-‐Explain primary effects and recency effects.

-‐Using principles from information-‐processing theories, how can we make learning more efficient and effective?



3 Theory in Action

-‐Examine the strategies in the following resources. Identify the underlying principle/s behind each strategy—why/how does each work? -‐-‐12 Great Memory Strategies For Better Grades -‐-‐Using Memory Effectively -‐-‐20 Ways to Improve Your Memory -‐Attempt to quickly memorize the two sets of letters below. Which set was easier to remember? Did you realize that both sets contained the same letters, except that the second set has been organized in manageable (5 words versus 30 letters) and meaningful chunks (meaningful words versus nonsense letters)?

-‐E L I M S W O R R O M O T T E G R O F K O O B Y T I C

-‐CITY, BOOK, FORGET, TOMORROW, SMILE. -‐Why is it important to organize large amounts of information in “manageable” chunks? -‐ Why do phone numbers almost always have 7 digits?



4 Discussions

The forum is open for any related discussion and must not be limited to the following suggestion/s. You may generate your own questions/ discussion threads. 1. What implications do differences in declarative and procedural knowledge have for instruction? Where should our emphasis be as far as learning is concerned? 2. Consider the different ways attention is allocated (selective, divided, sustained, and executive). Cite how each operated in learning situations. Use your understanding of these processes to explain how learning is either enhanced or impaired in the situations you cited. Make recommendations when appropriate. 3. How may we use our understanding of primacy-‐recency effect in the classroom? 4. Plan ways to improve your current (a) teaching practice and (b) learning strategies by applying some principles from this module. (c) Identify the principle.



1. COGNITIVE PSYCHOLOGY (MACLEAOD, 2007) (http://www.simplypsychology.org/cognitive.html) Cognition – knowing -‐refers to the study of human mental processes and their role in thinking, feeling and behaving. -‐focuses on the way humans process information HUMAN INFORMATION PROCESS-‐ looking at how we treat information that comes in to the person (what behaviorists would call stimuli), and how this treatment leads to responses -‐interested in the variables that mediate between stimulus/input and response/output. -‐a study about internal processes including perception, attention, language, memory and thinking.



COGNITIVE PSYCHOLOGY -‐nomothetic idiographic approach -‐-‐nomothetic – laws and generalization -‐-‐idiographic – own or private -‐reductionist approach -‐-‐reductionist – the belief that human behavior can be explained by breaking it down into smaller component parts. -‐-‐-‐the best way to understand why we behave as we do is to look closely at the very simplest parts that make up our systems, and use the simplest explanations to understand how they work. -‐-‐-‐This means that all behaviour, no matter how complex can be reduced to simple cognitive processes, like memory or perception. Cognitive approach is a scientific one that is why psychologist use laboratory experiment to test it. COGNITIVE PSYCHOLOGY FACTORS -‐Dissatisfaction with the behaviorist approach in its simple emphasis on external behavior rather than internal processes. -‐The development of better experimental methods. -‐Comparison between human and computer processing of information. INFORMATION PROCESSING APPROACH 1. Information made available from the environment is processed by a series of processing systems (e.g. attention, perception, short-‐term memory); 2. These processing systems transform, or alter the information in systematic ways; 3.The aim of research is to specify the processes and structures that underlie cognitive performance; 4.Information processing in humans resembles that in computers.



MEDIATIONAL PROCESSES The behaviorists approach only studies external observable (stimulus and response) behaviour which can be objectively measured. They believe that internal behaviour cannot be studied because we cannot see what happens in a person’s mind (and therefore cannot objectively measure it). In comparison, the cognitive approach believes that internal mental behaviour can be scientifically studied using experiments. Cognitive psychology assumes that a mediational process occurs between stimulus/input and response/output.



COGNITIVE PSYCHOLOGY HISTORY -‐revolutionarize in the late 1950’s and 1960’s -‐dominant approach in 1970’s (perspective) -‐Piaget and Tolman -‐arrival of computer -‐ allowed psychologists to try to understand the complexities of human cognition by comparing it with something simpler and better understood i.e. an artificial system such as a computer. -‐ The idea of information processing was adopted by cognitive psychologists as a model of how human thought works.

-‐Norbert Wiener (1948) published Cybernetics: or Control and Communication in the Animal and the Machine, introducing terms such as input and output. -‐Tolman (1948) work on cognitive maps – training rats in mazes, showed that animals had internal representation of behavior. -‐Birth of Cognitive Psychology often dated back to George Miller’s (1956) “The Magical Number 7 Plus or Minus 2.” -‐Newell and Simon’s (1972) development of the General Problem Solver. -‐In 1960, Miller founded the Center for Cognitive Studies at Harvard with famous cognitive developmentalist, Jerome Bruner. -‐Ulric Neisser (1967) publishes "Cognitive Psychology", which marks the official beginning of the cognitive approach. -‐Process models of memory Atkinson & Shiffrin’s (1968) Multi Store Model. -‐Cognitive approach highly influential in all areas of psychology (e.g. biological, social, behaviorism, development etc.).



KEY FEATURES -‐Mediational Processes -‐Information Processing -‐Computer Analogy -‐Introspection (Wundt) -‐Nomothetic (studies the group) -‐Schema -‐Machine Reductionism BASIC ASSUMPTIONS -‐Cognitive psychology is a pure science, based mainly on laboratory experiments. -‐Behavior can be largely explained in terms of how the mind operates, i.e. the information processing approach. -‐The mind works in a way similar to a computer: inputting, storing and retrieving data. -‐Mediational processes occur between stimulus and response. STRENGTHS -‐Scientific -‐Highly applicable (e.g. therapy, EWT) -‐Combines easily with approaches: behaviorism + Cog = Social Learning Biology + Cog = Evolutionary Psy

-‐Many empirical studies to support theories LIMITATIONS -‐Ignores biology (e.g. testosterone) -‐Experiments -‐ low ecological validity -‐Humanism -‐ rejects scientific method -‐Behaviorism -‐ can’t objectively study unobservable behavior -‐Introspection is subjective -‐Machine reductionism METHODOLOGY -‐Lab Experiments -‐Introspection (Wundt) -‐Memory Psychology -‐Interviews (Kohlberg, Piaget) -‐Case Studies (KF, HM ) -‐Observations (Piaget) -‐Computer Modeling



METHODOLOGY -‐Moral Development (Kohlberg, Piaget) -‐Eyewitness Testimony -‐Memory -‐Forgetting -‐Selective Attention -‐Perception -‐Child Development (Piaget) -‐Language Acquisition -‐Cognitive Behavioral Therapy -‐Learning Styles (Kolb) -‐Information Processing -‐Cognitive Interview -‐Education (Vygotsky, Bruner, Piaget) -‐Abnormal Behavior (e.g. Depression CRITICAL EVALUATION B.F. Skinner criticizes the cognitive approach as he believes that only external stimulus -‐ response behavior should be studied as this can be scientifically measured. Therefore, mediation processes (between stimulus and response) do not exist as they cannot be seen and measured. Skinner continues to find problems with cognitive research methods, namely introspection (as used by Wilhelm Wundt) due to its subjective and unscientific nature. Humanistic psychologist Carl Rogers believes that the use of laboratory experiments by cognitive psychology have low ecological validity and create an artificial environment due to the control over variables. Rogers emphasizes a more holistic approach to understanding behavior. The information processing paradigm of cognitive psychology views that minds in terms of a computer when processing information. However, there are important difference between humans and computers. The mind does not process information like a computer as computers don’t have emotions or get tired like humans. Behaviorism assumes that people are born a blank slate (tabula rasa) and are not born with cognitive functions like schemas, memory or perception. The cognitive approach does not always recognize physical (re: biological psychology) and environmental (re: behaviorism) factors in determining behavior. Cognitive psychology has influenced and integrated with many other approaches and areas of study to produce, for example, social learning theory, cognitive neuropsychology and artificial intelligence (AI).



2. INFORMATION PROCESSING THEORY (SCHRAW & MCCRUDDENT, 2013/EDUCATION.COM) (http://www.education.com/reference/article/information-‐processing-‐theory/) INFORMATION PROCESSING MODEL -‐used as a metaphor for successful learning because it is well supported by research and provides a well-‐articulated means for describing the main cognitive structures (memory systems) and processes (strategies) in the learning cycle. THREE MAIN COMPONENTS OF INFORMATION PROCESSING THEORY 1. sensory memory 2. working memory 3. long-‐term memory 1. SENSORY MEMORY -‐together with working memory enable people to manage limited amoutns of incoming information during initial processing 2. WORKING MEMORY -‐together with sensory memory enable people to manage limited amoutns of incoming information during initial processing 3. LONG-‐TERM MEMORY -‐serves as repository for knowledge. 1. SENSORY MEMORY -‐Sensory memory processes incoming sensory information for very brief periods of time, usually on the order of 1/2 to 3 seconds. -‐The main purpose of sensory memory is to screen incoming stimuli and process only those stimuli that are most relevant at the present time. -‐information processing in sensory memory usually occurs too quickly for people to consciously control what they attend to -‐attention allocation and sensory processing are fast and unconscious. -‐Information that is relevant to the task at hand, and information that is familiar and therefore subject to automatic processing, are the most likely types of information to be processed in sensory memory and forwarded to the working memory buffer. -‐Information that is highly relevant may receive some degree of controlled, conscious processing if it is crucial to a task (e.g., attending to salient information such as animals along the road while driving at high speed). -‐Controlled processing in sensory memory would be likely further to reduce the limited amount of information that can be processed at any given moment. Attention allocation: fast and unconcious Sensory Processing: fast and unconcious Information relevant to the task at hand and familiar: subject to automatic processing Information highly relevant: controlled and conscious processing



2. WORKING MEMORY -‐Working memory is a term that is used to refer to a multi-‐component temporary memory system in which information is assigned meaning, linked to other information, and essential mental operations such as inferences are performed. -‐All individuals experience severe limitations in how much mental activity they can engage in due to limited cognitive resources (Kane & Engle, 2002). Although humans differ with respect to available cognitive resources, all learners experience severe limitations regardless of their skill and ability level. Often, differences between one learner and another are not due to the amount of resources, but how efficiently those resources are used. -‐Automaticity -‐ being able to perform a task very quickly and efficiently due to repeated practice (Stanovich, 2003) -‐ Automated activities usually require few cognitive resources; -‐Selective processing -‐ refers to the act of intentionally focusing one's limited cognitive resources on stimuli that are most relevant to the task at hand.

Figure 1 ILLUSTRATION BY GGS INFORMATION SERVICES. CENGAGE LEARNING, GALE.



BADDELEY’S 2001 MODEL THREE MAIN COMPONENTS OF INFORMATION PROCESSING THEORY 1. Executive Control System 2. Articulary Loop 3. Visual-‐Spatial Sketch Pad 1. EXECUTIVE CONTROL SYSTEM -‐select incoming information -‐determine how to best process that information -‐construct meaning through organization and inferences -‐transfer the information to long-‐term memory or choose to delete that information from the memory system altogether. Most models of working memory assume that the central executive is the place where humans “make conscious meaning” of the information they process (Shah & Miyake, 1999). 2. ARTICULARY LOOP -‐maintain and further process verbal information 3. VISUAL-‐SPATIAL SKETCH PAD -‐analogous to articulary loop in that it maintains and further processes non-‐verbal and visual information. -‐information is lost quickly from working memory (5 to 15 seconds) unless some type of mental rehearsal occurs. -‐Barring rehearsal – (ex. Repeating telephone number) information is either forwarded to long-‐term memory or is deleted from system

Table 1 ILLUSTRATION BY GGS INFORMATION SERVICES. CENGAGE LEARNING, GALE BADDELEY’S MODEL CRITICAL ASSUMPTIONS ABOUT PROCESSING OF INFORMATION IN WORKING MEMORY 1. Each of the three subsystems possesses its own pool of limited cognitive resources. -‐This means that, under normal information processing circumstances, each subsystem performs work without taxing the other subsystems. 2. The executive control system regulates the articulatory loop and visual-‐spatial sketch pad.



3. LONG-‐TERM MEMORY -‐Unlike sensory and working memory, long-‐term memory is not constrained by capacity or duration of attention limitations. -‐The role of long-‐term memory is to provide a seemingly unlimited repository for all the facts and knowledge in memory. -‐Most researchers believe that long-‐term memory is capable of holding millions of pieces of information for very long periods of time (Anderson, 2000). TWO ASPECTS OF LONG-‐TERM MEMORY a. What types of information are represented b. How information is organized Qualitatively different types of information exist in long-‐term memory and that information must be organized, and therefore quickly accessible, to be of practical use to learners. -‐Figure 1 shows that working memory and long-‐term memory are connected by encoding and retrieval processes. -‐Encoding refers to a large number of strategies that move information from temporary store in working memory into long-‐term memory. -‐-‐Examples include organization, inference, and elaboration strategies, which will be discussed later. -‐Retrieval refers to processes that enable individuals to search memory and access information for active processing in working memory. -‐Both encoding and retrieval greatly facilitate learning when information in long-‐term memory is organized for easy access. -‐A comparison of the three components of the IPM indicates that both sensory and working memory are relatively short term in nature (see Table 1). Their main roles are to screen incoming information, assign meaning, and relate individual units of information to other units. -‐In contrast, the main role of long-‐term memory is to serve as a highly organized permanent storage system. -‐Sensory and working memory process few pieces of information within a short time frame. Automaticity of processing and selective allocation of limited cognitive resources greatly increases the efficiency of information processing.



-‐Long-‐term memory is assumed to be more or less permanent and unlimited in terms of capacity. -‐The main processing constraint on long-‐term memory is the individual's ability to quickly encode and retrieve information using an efficient organizational system. The information processing model provides a conceptual model which explains the different functions and constraints on human memory. The IPM also has had a major impact on instructional theory and practice. Sweller and Chandler's 1994 work developed cognitive load theory to explain how different instructional and learner constraints affect optimal information processing. The crux of their argument is that each task imposes some degree of cognitive load, which must be met either by available cognitive resources or learner-‐based strategies such as selective attention and automaticity. Reducing cognitive load enables individuals to learn with less overall mental effort. Cognitive load theory has been especially helpful in terms of planning instruction and developing learning materials. Others researchers such as Mayer and Moreno (2003) have developed frameworks to increase learning by systematically reducing cognitive load through better design of learning materials and more strategic use of limited resources by students. In summary, the information processing model postulates a three-‐component model of information processing. The IPM is consistent with empirical findings and provides an excellent framework for understanding principles of effective learning, which are considered later in this entry. Sensory and working memory are limited with respect to capacity and duration, whereas long-‐term memory is more or less unlimited. Information processing efficiency is increased due to automaticity and selectivity. Encoding and retrieval of information in long-‐term memory is increased due to efficient organizational strategies.



IMPLICATIONS OF INFORMATION PROCESSING TO INSTRUCTIONS -‐The information processing model provides four important implications for improving learning and instruction. 1. Memory stores are extremely limited in both sensory and working memory. The two main strategies that effective learners use to cope with limited capacity are: a.) Selectively focusing their attention on important information b.)Engaging in as much automated processing as possible. From an educational perspective: It is essential for students to become automated at basic skills such as letter and word decoding, number recognition, and simple procedural skills such as handwriting, multiplication, and spelling. Automaticity makes available limited processing resources that can be used to engage in labor intensive self-‐regulation (Butler & Winne, 1995; Zeidner, Boekaerts, & Pintrich, 2000; Zimmerman, 2000) and comprehension monitoring (Schraw, 2001; Sternberg, 2001). 2. Relevant prior knowledge facilitates encoding and retrieval processes. Highly effective learners possess a great deal of organized knowledge within a particular domain such as reading, mathematics, or science. They also possess general problem-‐solving and critical-‐thinking scripts that enable them to perform well across different domains. This knowledge guides information processing in sensory and working memory by providing easy-‐to-‐access retrieval structures in memory. It also serves as the basis for the development of expertise (Alexander, 2003; Ericsson, 2003). Thus, helping students use their prior knowledge when learning new information promotes learning. 3. Automated information processing increases cognitive efficiency by reducing information processing demands. Automaticity is an important aspect of effective learning for two reasons. a.) Being automated makes it easier selectively to allocate limited resources to information that is most relevant to the task at hand. Unfortunately, there is no easy road to automaticity other than sustained, regular practice. b.) Automaticity frees limited resources that can be used for other activities such as drawing inferences and connecting new information to existing information in memory.



4. Learning strategies improve information processing because learners are more efficient and process information at a deeper level (Pressley & Harris, 2006; Pressley & McDonald-‐Wharton, 1997). All effective learners draw from a repertoire of learning strategies in a flexible manner. Some of these strategies are used automatically, while some require controlled processing and metacognitive control that place high demands on limited cognitive resources. Good learners use a wide variety of strategies and use them in a highly automatic fashion. Three general strategies that all effective learners use in most situations: (Mayer & Moreno, 2003) a.) Organization b.) Inferences c.) Elaboration a.) Organization refers to how information is sorted and arranged in long-‐term memory. Information that is related to what one already knows is easier to encode and retrieve than isolated information. In some cases, individuals already possess well organized knowledge with empty slots that can be filled easily with new information. Activating existing knowledge prior to instruction, or providing a visual diagram of how information is organized, is one of the best ways to facilitate learning new information. b.) Constructing inferences involves making connections between separate concepts. c.) Elaboration refers to increasing the meaningfulness of information by connecting new information to ideas already known.



3. TYPES OF MEMORY (http://www.human-‐memory.net/types.html) THREE STAGES OF MEMORY (BY ATKINSON-‐ SHIFFRIN MODEL) (1968) 1. Sensory 2. Short Term 3. Long-‐Term PROCESS OF MEMORY 1. Encoding 2. Consolidation 3. Storage 4. Recall PROCESS OF MEMORY (BY FERGUS CRAIK AND ROBERT LOCHART) 1. Recall – something is memorized 2. Continous Scale from shallow (perceptual) to 3. Deep (Semantic)



What we usually think of as �memory� in day-‐to-‐day usage is actually long-‐term memory, but there are also important short-‐term and sensory memory processes, which must be worked through before a long-‐term memory can be established. The different types of memory each have their own particular mode of operation, but they all cooperate in the process of memorization, and can be seen as three necessary steps in forming a lasting memory. This model of memory as a sequence of three stages, from sensory to short-‐term to long-‐term memory, rather than as a unitary process, is known as the modal or multi-‐store or Atkinson-‐Shiffrin model, after Richard Atkinson and Richard Shiffrin who developed it in 1968, and it remains the most popular model for studying memory. It is often also described as the process of memory, but I have used this description for the processes of encoding, consolidation, storage and recall in the separate Memory Processes section. It should be noted that an alternative model, known as the levels-‐of-‐processing model was proposed by Fergus Craik and Robert Lockhart in 1972, and posits that memory recall, and the extent to which something is memorized, is a function of the depth of mental processing, on a continuous scale from shallow (perceptual) to deep (semantic). Under this model, there is no real structure to memory and no distinction between short-‐term and long-‐term memory.

SENSORY MEMORY Sensory memory is the shortest-‐term element of memory. It is the ability to retain impressions of sensory information after the original stimuli have ended. It acts as a kind of buffer for stimuli received through the five senses of sight, hearing, smell, taste and touch, which are retained accurately, but very briefly. For example, the ability to look at something and remember what it looked like with just a second of observation is an example of sensory memory. The stimuli detected by our senses can be either deliberately ignored, in which case they disappear almost instantaneously, or perceived, in which case they enter our sensory memory. This does not require any conscious attention and, indeed, is usually considered to be totally outside of conscious control. The brain is designed to only process information that will be useful at a later date, and to allow the rest to pass by unnoted. As information is perceived, it is therefore stored in sensory memory automatically and unbidden. Unlike other types of memory, the sensory memory cannot be prolonged via rehearsal. Sensory memory is an ultra-‐short-‐term memory and decays or degrades very quickly, typically in the region of 200 -‐ 500 milliseconds (1/5 -‐ 1/2 second) after the perception of an item, and certainly less than a second (although echoic memory is now thought to last a little longer, up to perhaps three or four seconds). Indeed, it lasts for such a short time that it is often considered part of the process of perception, but it nevertheless represents an essential step for storing information in short-‐term memory.



The sensory memory for visual stimuli is sometimes known as the iconic memory, the memory for aural stimuli is known as the echoic memory, and that for touch as the haptic memory. Smell may actally be even more closely linked to memory than the other senses, possibly because the olfactory bulb and olfactory cortex (where smell sensations are processed) are physically very close -‐ separated by just 2 or 3 synapses -‐ to the hippocampus and amygdala (which are involved in memory processes). Thus, smells may be more quickly and more strongly associated with memories and their associated emotions than the other senses, and memories of a smell may persist for longer, even without constant re-‐consolidation. Experiments by George Sperling in the early 1960s involving the flashing of a grid of letters for a very short period of time (50 milliseconds) suggest that the upper limit of sensory memory (as distinct from short-‐term memory) is approximately 12 items, although participants often reported that they seemed to "see" more than they could actually report. Information is passed from the sensory memory into short-‐term memory via the process of attention (the cognitive process of selectively concentrating on one aspect of the environment while ignoring other things), which effectively filters the stimuli to only those which are of interest at any given time. SHORT-‐TERM (WORKING) MEMORY Short-‐term memory acts as a kind of �scratch-‐pad� for temporary recall of the information which is being processed at any point in time, and has been refered to as "the brain's Post-‐it note". It can be thought of as the ability to remember and process information at the same time. It holds a small amount of information (typically around 7 items or even less) in mind in an active, readily-‐available state for a short period of time (typically from 10 to 15 seconds, or sometimes up to a minute). For example, in order to understand this sentence, the beginning of the sentence needs to be held in mind while the rest is read, a task which is carried out by the short-‐term memory. Other common examples of short-‐term memory in action are the holding on to a piece of information temporarily in order to complete a task (e.g. �carrying over� a number in a subtraction sum, or remembering a persuasive argument until another person finishes talking), and simultaneous translation (where the interpreter must store information in one language while orally translating it into another). What is actually held in short-‐term memory, though, is not complete concepts,but rather links or pointers (such as words, for example) which the brain can flesh out from it's other accumulated knowledge. However, this information will quickly disappear forever unless we make a conscious effort to retain it, and short-‐term memory is a necessary step toward the next stage of retention, long-‐term memory. The transfer of information to long-‐term memory for more permanent storage can be facilitated or improved by mental repetition of the information or, even more effectively, by giving it a meaning and associating it with other previously acquired knowledge. Motivation is also a consideration, in that information relating to a subject of strong interest to a person, is more likely to be retained in long-‐term memory.



The term working memory is often used interchangeably with short-‐term memory, although technically working memory refers more to the whole theoretical framework of structures and processes used for the temporary storage and manipulation of information, of which short-‐term memory is just one component. The central executive part of the prefrontal cortex at the front of the brain appears to play a fundamental role in short-‐term and working memory. It both serves as a temporary store for short-‐term memory, where information is kept available while it is needed for current reasoning processes, but it also "calls up" information from elsewhere in the brain. The central executive controls two neural loops, one for visual data (which activates areas near the visual cortex of the brain and acts as a visual scratch pad), and one for language (the "phonological loop", which uses Broca's area as a kind of "inner voice" that repeats word sounds to keep them in mind). These two scratch pads temporarily hold data until it is erased by the next job. Although the prefrontal cortex is not the only part of the brain involved -‐ it must also cooperate with other parts of the cortex from which it extracts information for brief periods -‐ it is the most important, and Carlyle Jacobsen reported, as early as 1935, that damage to the prefrontal cortex in primates caused short-‐term memory deficits. The short-‐term memory has a limited capacity, which can be readily illustrated by the simple expedient of trying to remember a list of random items (without allowing repetition or reinforcement) and seeing when errors begin to creep in. The often-‐cited experiments by George Miller in 1956 suggest that the number of objects an average human can hold in working memory (known as memory span) is between 5 and 9 (7 � 2, which Miller described as the �magical number�, and which is sometimes referred to as Miller's Law). However, although this may be approximately true for a population of college students, for example, memory span varies widely with populations tested, and modern estimates are typically lower, of the order of just 4 or 5 items. The type or characteristics of the information also affects the number of items which can be retained in short-‐term memory. For instance, more words can be recalled if they are shorter or more commonly used words, or if they are phonologically similar in sound, or if they are taken from a single semantic category (such as sports, for example) rather than from different categories, etc. There is also some evidence that short-‐term memory capacity and duration is increased if the words or digits are articulated aloud instead of being read sub-‐vocally (in the head). The relatively small capacity of the short-‐term memory, compared to the huge capacity of long-‐term memory, has been attributed by some to the evolutionary survival advantage in paying attention to a relatively small number of important things (e.g. the approach of a dangerous predator, the proximity of a nearby safe haven, etc) and not to a plethora of other peripheral details which would only interfere with rapid decision-‐making.



"Chunking" of information can lead to an increase in the short-‐term memory capacity. Chunking is the organization of material into shorter meaningful groups to make them more manageable. For example, a hyphenated phone number, split into groups of 3 or 4 digits, tends to be easier to remember than a single long number. Experiments by Herbert Simon have shown that the ideal size for chunking of letters and numbers, whether meaningful or not, is three. However, meaningful groups may be longer (such as four numbers that make up a date within a longer list of numbers, for example). With chunking, each chunk represents just one of the 5 -‐ 9 items that can be stored in short-‐term memory, thus extending the total number of items that can be held. It is usually assumed that the short-‐term memory spontaneously decays over time, typically in the region of 10 -‐ 15 seconds, but items may be retained for up to a minute, depending on the content. However, it can be extended by repetition or rehearsal (either by reading items out loud, or by mental simulation), so that the information re-‐enters the short-‐term store and is retained for a further period. When several elements (such as digits, words or pictures) are held in short-‐term memory simultaneously, they effectively compete with each other for recall. New content, therefore, gradually pushes out older content (known as displacement), unless the older content is actively protected against interference by rehearsal or by directing attention to it. Any outside interference tends to cause disturbances in short-‐term memory retention, and for this reason people often feel a distinct desire to complete the tasks held in short-‐term memory as soon as possible. The forgetting of short-‐term memories involves a different process to the forgetting of long-‐term memories. When something in short-‐term memory is forgotten, it means that a nerve impulse has merely ceased being transmitted through a particular neural network. In general, unless an impulse is reactivated, it stops flowing through a network after just a few seconds. Typically, information is transferred from the short-‐term or working memory to the long-‐term memory within just a few seconds, although the exact mechanisms by which this transfer takes place, and whether all or only some memories are retained permanently, remain controversial topics among experts. Richard Schiffrin, in particular, is well known for his work in the 1960s suggesting that ALL memories automatically pass from a short-‐term to a long-‐term store after a short time (known as the modal or multi-‐store or Atkinson-‐Schiffrin model). However, this is disputed, and it now seems increasingly likely that some kind of vetting or editing procedure takes place. Some researchers (e.g. Eugen Tarnow) have proposed that there is no real distinction between short-‐term and long-‐term memory at all, and certainly it is difficult to demarcate a clear boundary between them. However, the evidence of patients with some kinds of anterograde amnesia, and experiments on the way distraction affect the short-‐term recall of lists, suggest that there are in fact two more or less separate systems.



LONG-‐TERM MEMORY Long-‐term memory is, obviously enough, intended for storage of information over a long period of time. Despite our everyday impressions of forgetting, it seems likely that long-‐term memory actually decays very little over time, and can store a seemingly unlimited amount of information almost indefinitely. Indeed, there is some debate as to whether we actually ever �forget� anything at all, or whether it just becomes increasingly difficult to access or retrieve certain items from memory. Short-‐term memories can become long-‐term memory through the process of consolidation, involving rehearsal and meaningful association. Unlike short-‐term memory (which relies mostly on an acoustic, and to a lesser extent a visual, code for storing information), long-‐term memory encodes information for storage semantically (i.e. based on meaning and association). However, there is also some evidence that long-‐term memory does also encode to some extent by sound. For example, when we cannot quite remember a word but it is �on the tip of the tongue�, this is usually based on the sound of a word, not its meaning. Physiologically, the establishment of long-‐term memory involves a process of physical changes in the structure of neurons (or nerve cells) in the brain, a process known as long-‐term potentiation, although there is still much that is not completely understood about the process. At its simplest, whenever something is learned, circuits of neurons in the brain, known as neural networks, are created, altered or strengthened. These neural circuits are composed of a number of neurons that communicate with one another through special junctions called synapses. Through a process involving the creation of new proteins within the body of neurons, and the electrochemical transfer of neurotransmitters across synapse gaps to receptors, the communicative strength of certain circuits of neurons in the brain is reinforced. With repeated use, the efficiency of these synapse connections increases, facilitating the passage of nerve impulses along particular neural circuits, which may involve many connections to the visual cortex, the auditory cortex, the associative regions of the cortex, etc. This process differs both structurally and functionally from the creation of working or short-‐term memory. Although the short-‐term memory is supported by transient patterns of neuronal communication in the regions of the frontal, prefrontal and parietal lobes of the brain, long-‐term memories are maintained by more stable and permanent changes in neural connections widely spread throughout the brain. The hippocampus area of the brain essentially acts as a kind of temporary transit point for long-‐term memories, and is not itself used to store information. However, it is essential to the consolidation of information from short-‐term to long-‐term memory, and is thought to be involved in changing neural connections for a period of three months or more after the initial learning.



Unlike with short-‐term memory, forgetting occurs in long-‐term memory when the formerly strengthened synaptic connections among the neurons in a neural network become weakened, or when the activation of a new network is superimposed over an older one, thus causing interference in the older memory. Over the years, several different types of long-‐term memory have been distinguished, including explicit and implicit memory, declarative and procedural memory (with a further sub-‐division of declarative memory into episodic and semantic memory) and retrospective and prospective memory. DECLARATIVE (EXPLICIT) & PROCEDURAL (IMPLICIT) MEMORY Long-‐term memory is often divided into two further main types: explicit (or declarative) memory and implicit (or procedural) memory. Declarative memory (�knowing what�) is memory of facts and events, and refers to those memories that can be consciously recalled (or "declared"). It is sometimes called explicit memory, since it consists of information that is explicitly stored and retrieved, although it is more properly a subset of explicit memory. Declarative memory can be further sub-‐divided into episodic memory and semantic memory. Procedural memory (�knowing how�) is the unconscious memory of skills and how to do things, particularly the use of objects or movements of the body, such as tying a shoelace, playing a guitar or riding a bike. These memories are typically acquired through repetition and practice, and are composed of automatic sensorimotor behaviours that are so deeply embedded that we are no longer aware of them. Once learned, these "body memories" allow us to carry out ordinary motor actions more or less automatically. Procedural memory is sometimes referred to as implicit memory, because previous experiences aid in the performance of a task without explicit and conscious awareness of these previous experiences, although it is more properly a subset of implicit memory. These different types of long-‐term memory are stored in different regions of the brain and undergo quite different processes. Declarative memories are encoded by the hippocampus, entorhinal cortex and perirhinal cortex (all within the medial temporal lobe of the brain), but are consolidated and stored in the temporal cortex and elsewhere. Procedural memories, on the other hand, do not appear to involve the hippocampus at all, and are encoded and stored by the cerebellum, putamen, caudate nucleus and the motor cortex, all of which are involved in motor control. Learned skills such as riding a bike are stored in the putamen; instinctive actions such as grooming are stored in the caudate nucleus; and the cerebellum is involved with timing and coordination of body skills. Thus, without the medial temporal lobe (the structure that includes the hippocampus), a person is still able to form new procedural memories (such as playing the piano, for example), but cannot remember the events during which they happened or were learned.



Perhaps the most famous study demonstrating the separation of the declarative and procedural memories is that of a patient known as �H.M.�, who had parts of his medial temporal lobe, hippocampus and amygdala removed in 1953 in an attempt to cure his intractable epilepsy. After the surgery, H.M. could still form new procedural memories and short-‐term memories, but long-‐lasting declarative memories could no longer be formed. The nature of the exact brain surgery he underwent, and the types of amnesia he experienced, allowed a good understanding of how particular areas of the brain are linked to specific processes in memory formation. In particular, his ability to recall memories from well before his surgery, but his inability to create new long-‐term memories, suggests that encoding and retrieval of long-‐term memory information is mediated by distinct systems within the medial temporal lobe, particularly the hippocampus. The fact that he was able to learn hand-‐eye coordination skills such as mirror drawing, despite having absolutely no memory of having learned or practised the task before, also suggested the existence different types of long-‐term memory, which are now known as declarative and procedural memories There is strong evidence, notably by studying amnesic patients and the effect of priming, to suggest that implicit memory is largely distinct from explicit memory, and operates through a different process in the brain. Studies of the effects of amnesia have shown that it is quite possible to have an intact implicit memory despite a severely impaired explicit memory. Priming is the effect in which exposure to a stimulus influences response to a subsequent stimulus, so that, for instance, if a person reads a list of words including the word �concert�, and is later asked to complete a word starting with �con�, there is a higher probability that they will answer �concert� than, say, �contact�, �connect�, etc. Studies from amnesic patients indicate that priming is controlled by a brain system separate from the medial temporal system that supports explicit memory. EPISODIC & SEMANTIC MEMORY Declarative memory can be further sub-‐divided into episodic memory and semantic memory. Episodic memory represents our memory of experiences and specific events in time in a serial form, from which we can reconstruct the actual events that took place at any given point in our lives. It is the memory of autobiographical events (times, places, associated emotions and other contextual knowledge) that can be explicitly stated. Individuals tend to see themselves as actors in these events, and the emotional charge and the entire context surrounding an event is usually part of the memory, not just the bare facts of the event itself. Semantic memory, on the other hand, is a more structured record of facts, meanings, concepts and knowledge about the external world that we have acquired. It refers to general factual knowledge, shared with others and independent of personal experience and of the spatial/temporal context in which it was acquired. Semantic memories may once have had a personal context, but now stand alone as simple knowledge. It therefore includes such things as types of food, capital cities, social customs, functions of objects, vocabulary, understanding of mathematics, etc. Much of semantic memory is abstract and relational and is associated with the meaning of verbal symbols.



The semantic memory is generally derived from the episodic memory, in that we learn new facts or concepts from our experiences, and the episodic memory is considered to support and underpin semantic memory. A gradual transition from episodic to semantic memory can take place, in which episodic memory reduces its sensitivity and association to particular events, so that the information can be generalized as semantic memory. Both episodic memory and semantic memory require a similar encoding process. However, semantic memory mainly activates the frontal and temporal cortexes, whereas episodic memory activity is concentrated in the hippocampus, at least initially. Once processed in the hippocampus, episodic memories are then consolidated and stored in the neocortex. The memories of the different elements of a particular event are distributed in the various visual, olfactory and auditory areas of the brain, but they are all connected together by the hippocampus to form an episode, rather than remaining a collection of separate memories. For example, memories of people�s faces, the taste of the wine, the music that was playing, etc, might all be part of the memory of a particular dinner with friends. By repeatedly reactivating or �playing back� this particular activity pattern in the various regions of the cortex, they become so strongly linked with one another that they no longer need the hippocampus to act as their link, and the memory of the music that was playing that night, for example, can act as an index entry, and may be enough to bring back the entire scene of the dinner party. Our spatial memory in particular appears to be much more confined to the hippocampus, particularly the right hippocampus, which seems to be able to create a mental map of space, thanks to certain cells called "place cells". Episodic memory does also trigger activity in the temporal lobe, but mainly in order to ensure that these personal memories are not mistaken for real life. This difference in the neurological processing of episodic and semantic memory is illustrated by cases of anterograde amnesia cases (a good example being a case known as �C.L.�) in which episodic memory is almost completely lost while semantic memory is retained. A further category of declarative memory, referred to as autobiographical memory, is sometimes distinguished, although really it is just one area of episodic memory. Autobiographical memory refers to a memory system consisting of episodes recollected from an individual�s own life, often based on a combination of episodic memory (personal experiences and specific objects, people and events experienced at particular times and places) and semantic memory (general knowledge and facts about the world).



One specific type of autobiographical memory is known as a "flashbulb memory", a highly detailed, exceptionally vivid �snapshot� of a moment or circumstances in which surprising and consequential (or emotionally arousing) news was heard, famous examples being the assassination of John Kennedy, the terrorist bombings on 9/11, etc. Such memories are believed by some to be highly resistant to forgetting, possibly due to the strong emotions that are typically associated with them. However, a number of studies also suggest that flashbulb memories are actually not especially accurate, despite apparently being experienced with great vividness and confidence. RETROSPECTIVE & PROSPECTIVE MEMORY An important alternative classification of long-‐term memory used by some researchers is based on the temporal direction of the memories. Retrospective memory is where the content to be remembered (people, words, events, etc) is in the past, i.e. the recollection of past episodes. It includes semantic, episodic and autobiographical memory, and declarative memory in general, although it can be either explicit or implicit. Prospective memory is where the content is to be remembered in the future, and may be defined as �remembering to remember� or remembering to perform an intended action. It may be either event-‐based or time-‐based, often triggered by a cue, such as going to the doctor (action) at 4pm (cue), or remembering to post a letter (action) after seeing a mailbox (cue). Clearly, though, retrospective and prospective memory are not entirely independent entities, and certain aspects of retrospective memory are usually required for prospective memory. Thus, there have been case studies where an impaired retrospective memory has caused a definite impact on prospective memory. However, there have also been studies where patients with an impaired prospective memory had an intact retrospective memory, suggesting that to some extent the two types of memory involve separate processes.



4. MEMORY PROCESSES (MASTIN,2010) (http://www.human-‐memory.net/processes.html) We have already looked at the different stages of memory formation (from perception to sensory memory to short-‐term memory to long-‐term memory) in the section on Types of Memory. This section, however, looks at the overall processes involved. Memory is the ability to encode, store and recall information. The three main processes involved in human memory are therefore encoding, storage and recall (retrieval). Additionally, the process of memory consolidation (which can be considered to be either part of the encoding process or the storage process) is treated here as a separate process in its own right. Some of the physiology and neurology involved in these processes is highly complex and technical (and some of it still not completely understood), and lies largely outside the remit of this entry level guide, although at least a general introduction is given here. More information on the architecture of the human brain, and the neurological processes by which memory is encoded, stored and recalled can be found in the section on Memory and the Brain.



MEMORY ENCODING Encoding is the crucial first step to creating a new memory. It allows the perceived item of interest to be converted into a construct that can be stored within the brain, and then recalled later from short-‐term or long-‐term memory. Encoding is a biological event beginning with perception through the senses. The process of laying down a memory begins with attention (regulated by the thalamus and the frontal lobe), in which a memorable event causes neurons to fire more frequently, making the experience more intense and increasing the likelihood that the event is encoded as a memory. Emotion tends to increase attention, and the emotional element of an event is processed on an unconscious pathway in the brain leading to the amygdala. Only then are the actual sensations derived from an event processed. The perceived sensations are decoded in the various sensory areas of the cortex, and then combined in the brain�s hippocampus into one single experience. The hippocampus is then responsible for analyzing these inputs and ultimately deciding if they will be committed to long-‐term memory. It acts as a kind of sorting centre where the new sensations are compared and associated with previously recorded ones. The various threads of information are then stored in various different parts of the brain, although the exact way in which these pieces are identified and recalled later remains largely unknown. The key role that the hippocampus plays in memory encoding has been highlighted by examples of individuals who have had their hippocampus damaged or removed and can no longer create new memories (see Anterograde Amnesia). It is also one of the few areas of the brain where completely new neurons can grow. Although the exact mechanism is not completely understood, encoding occurs on different levels, the first step being the formation of short-‐term memory from the ultra-‐short term sensory memory, followed by the conversion to a long-‐term memory by a process of memory consolidation. The process begins with the creation of a memory trace or engram in response to the external stimuli. An engram is a hypothetical biophysical or biochemical change in the neurons of the brain, hypothetical in the respect that no-‐one has ever actually seen, or even proved the existence of, such a construct. An organ called the hippocampus, deep within the medial temporal lobe of the brain, receives connections from the primary sensory areas of the cortex, as well as from associative areas and the rhinal and entorhinal cortexes. While these anterograde connections converge at the hippocampus, other retrograde pathways emerge from it, returning to the primary cortexes. A neural network of cortical synapses effectively records the various associations which are linked to the individual memory.



There are three or four main types of encoding: • Acoustic encoding is the processing and encoding of sound, words and other auditory

input for storage and later retrieval. This is aided by the concept of the phonological loop, which allows input within our echoic memory to be sub-‐vocally rehearsed in order to facilitate remembering.

• Visual encoding is the process of encoding images and visual sensory information. Visual sensory information is temporarily stored within the iconic memory before being encoded into long-‐term storage. The amygdala (within the medial temporal lobe of the brain which has a primary role in the processing of emotional reactions) fulfills an important role in visual encoding, as it accepts visual input in addition to input from other systems and encodes the positive or negative values of conditioned stimuli.

• Tactile encoding is the encoding of how something feels, normally through the sense of touch. Physiologically, neurons in the primary somatosensory cortex of the brain react to vibrotactile stimuli caused by the feel of an object.

• Semantic encoding is the process of encoding sensory input that has particular meaning or can be applied to a particular context, rather than deriving from a particular sense.

It is believed that, in general, encoding for short-‐term memory storage in the brain relies primarily on acoustic encoding, while encoding for long-‐term storage is more reliant (although not exclusively) on semantic encoding. Human memory is fundamentally associative, meaning that a new piece of information is remembered better if it can be associated with previously acquired knowledge that is already firmly anchored in memory. The more personally meaningful the association, the more effective the encoding and consolidation. Elaborate processing that emphasizes meaning and associations that are familiar tends to leads to improved recall. On the other hand, information that a person finds difficult to understand cannot be readily associated with already acquired knowledge, and so will usually be poorly remembered, and may even be remembered in a distorted form due to the effort to comprehend its meaning and associations. For example, given a list of words like "thread", "sewing", "haystack", "sharp", "point", "syringe", "pin", "pierce", "injection" and "knitting", people often also (incorrectly) remember the word "needle" through a process of association. Because of the associative nature of memory, encoding can be improved by a strategy of organization of memory called elaboration, in which new pieces of information are associated with other information already recorded in long-‐term memory, thus incorporating them into a broader, coherent narrative which is already familiar. An example of this kind of elaboration is the use of mnemonics, which are verbal, visual or auditory associations with other, easy-‐to-‐remember constructs, which can then be related back to the data that is to be remembered. Rhymes, acronymns, acrostics and codes can all be used in this way. Common examples are �Roy G. Biv� to remember the order of the colours of the rainbow, or �Every Good Boy Deserves Favour� for the musical notes on the lines of the treble clef, which most people find easier to remember than the original list of colours or letters.



When we use mnemonic devices, we are effectively passing facts through the hippocampus several times, so that it can keep strengthening the associations, and therefore improve the likelihood of subsequent memory recall. In the same way, associating words with images is another commonly used mnemonic device, providing two alternative methods of remembering, and creating additional associations in the mind. Taking this to a higher level, another method of improving memory encoding and consolidation is the use of a so-‐called memory palace (also known as the method of loci), a mnemonic techniques that relies on memorized spatial relationships to establish, order and recollect other memories. The method is to assign objects or facts to different rooms in an imaginary house or palace, so that recall of the facts can be cued by mentally �walking though� the palace until it is found. Many top memorizers today use the memory palace method to a greater or lesser degree. Similar techniques involve placing the items at different landmarks on a favourite hike or trip (known as the journey method), or weaving them into a story. The old and popular notion of the brain as a kind of �muscle� which strengthens with repeated use (also known as faculty theory) is now largely discredited. Research, dating back to William James towards the end of the 19th Century, shows that long hours spent memorizing does not build up the powers of memory at all, and, on the contrary, may even diminish it. This is not to say that individual memories cannot be strengthened by repetition, but that, as James found, daily training in the memorization of a poetry of one author, for example, does not improves a person�s ability to learn the poetry of another author, or poetry in general. Many studies have shown that the most vivid autobiographical memories tend to be of emotional events, which are likely to be recalled more often and with more clarity and detail than neutral events. One theory suggests that high levels of emotional arousal lead to attention narrowing, where the range of sensitive cues from the stimulus and its environment is decreased, so that information central to the source of the emotional arousal is strongly encoded while peripheral details are not (e.g. the so-‐called �weapon focus effect�, in which witnesses to a crime tend to remember the gun or knife in great detail, but not other more peripheral details such as the perpetrator�s clothing or vehicle).



MEMORY CONSOLIDATION Consolidation is the processes of stabilizing a memory trace after the initial acquisition. It may perhaps be thought of part of the process of encoding or of storage, or it may be considered as a memory process in its own right. It is usually considered to consist of two specific processes, synaptic consolidation (which occurs within the first few hours after learning or encoding) and system consolidation (where hippocampus-‐dependent memories become independent of the hippocampus over a period of weeks to years). Neurologically, the process of consolidation utilizes a phenomenon called long-‐term potentiation, which allows a synapse to increase in strength as increasing numbers of signals are transmitted between the two neurons. Potentiation is the process by which synchronous firing of neurons makes those neurons more inclined to fire together in the future. Long-‐term potentiation occurs when the same group of neurons fire together so often that they become permanently sensitized to each other. As new experiences accumulate, the brain creates more and more connections and pathways, and may �re-‐wire� itself by re-‐routing connections and re-‐arranging its organization. As such a neuronal pathway, or neural network, is traversed over and over again, an enduring pattern is engraved and neural messages are more likely to flow along such familiar paths of least resistance. This process is achieved by the production of new proteins to rebuild the synapses in the new shape, without which the memory remains fragile and easily eroded with time. For example, if a piece of music is played over and over, the repeated firing of certain synapses in a certain order in your brain makes it easier to repeat this firing later on, with the result that the musician becomes better at playing the music, and can play it faster, with fewer mistakes. In this way, the brain organizes and reorganizes itself in response to experiences, creating new memories prompted by experience, education or training. The ability of the connection, or synapse, between two neurons to change in strength, and for lasting changes to occur in the efficiency of synaptic transmission, is known as synaptic plasticity or neural plasticity, and it is one of the important neurochemical foundations of memory and learning. It should be remembered that each neuron makes thousands of connections with other neurons, and memories and neural connections are mutually interconnected in extremely complex ways. Unlike the functioning of a computer, each memory is embedded in many connections, and each connection is involved in several memories. Thus, multiple memories may be encoded within a single neural network, by different patterns of synaptic connections. Conversely, a single memory may involve simultaneously activating several different groups of neurons in completely different parts of the brain. The inverse of long-‐term potentiation, known as long-‐term depression, can also take place, whereby the neural networks involved in erroneous movements are inhibited by the silencing of their synaptic connections. This can occur in the cerebellum, which is located towards the back of the brain, in order to correct our motor procedures when learning how to perform a task (procedural memory), but also in the synapses of the cortex, the hippocampus, the striatum and other memory-‐related structures.



Contrary to long-‐term potentiation, which is triggered by high-‐frequency stimulation of the synapses, long-‐term depression is produced by nerve impulses reaching the synapses at very low frequencies, leading them to undergo the reverse transformation from long-‐term potentiation, and, instead of becoming more efficient, the synaptic connections are weakened. It is still not clear whether long-‐term depression contributes directly to the storage of memories in some way, or whether it simply makes us forget the traces of some things learned long ago so that new things can be learned. Sleep (particularly slow-‐wave, or deep, sleep, during the first few hours) is also thought to be important in improving the consolidation of information in memory, and activation patterns in the sleeping brain, which mirror those recorded during the learning of tasks from the previous day, suggest that new memories may be solidified through such reactivation and rehearsal. Memory re-‐consolidation is the process of previously consolidated memories being recalled and then actively consolidated all over again, in order to maintain, strengthen and modify memories that are already stored in the long-‐term memory. Several retrievals of memory (either naturally through reflection, or through deliberate recall) may be needed for long-‐term memories to last for many years, depending on the depth of the initial processing. However, these individual retrievals can take place at increasing intervals, in accordance with the principle of spaced repetition (this is familiar to us in the way that �cramming� the night before an exam is not as effective as studying at intervals over a much longer span of time). The very act of re-‐consolidation, though, may change the intial memory. As a particular memory trace is reactivated, the strengths of the neural connections may change, the memory may become associated with new emotional or environmental conditions or subsequently acquired knowledge, expectations rather than actual events may become incorporated into the memory, etc. Research into a cognitive disorder known as Korsakoff�s syndrome shows that the retrograde amnesia of sufferers follows a distinct temporal curve, in that the more remote the event in the past, the better it is preserved. This suggests that the more recent memories are not fully consolidated and therefore more vulnerable to loss, indicating that the process of consolidation may continue for much longer than initially thought, perhaps for many years. MEMORY STORAGE Storage is the more or less passive process of retaining information in the brain, whether in the sensory memory, the short-‐term memory or the more permanent long-‐term memory. Each of these different stages of human memory function as a sort of filter that helps to protect us from the flood of information that confront us on a daily basis, avoiding an overload of information and helping to keep us sane. The more the information is repeated or used, the more likely it is to be retained in long-‐term memory (which is why, for example, studying helps people to perform better on tests). This process of consolidation, the stabilizing of a memory trace after its initial acquisition, is treated in more detail in a separate section.



Since the early neurological work of Karl Lashley and Wilder Penfield in the 1950s and 1960s, it has become clear that long-‐term memories are not stored in just one part of the brain, but are widely distributed throughout the cortex. After consolidation, long-‐term memories are stored throughout the brain as groups of neurons that are primed to fire together in the same pattern that created the original experience, and each component of a memory is stored in the brain area that initiated it (e.g. groups of neurons in the visual cortex store a sight, neurons in the amygdala store the associated emotion, etc). Indeed, it seems that they may even be encoded redundantly, several times, in various parts of the cortex, so that, if one engram (or memory trace) is wiped out, there are duplicates, or alternative pathways, elsewhere, through which the memory may still be retrieved. Therefore, contrary to the popular notion, memories are not stored in our brains like books on library shelves, but must be actively reconstructed from elements scattered throughout various areas of the brain by the encoding process. Memory storage is therefore an ongoing process of reclassification resulting from continuous changes in our neural pathways, and parallel processing of information in our brains. The indications are that, in the absence of disorders due to trauma or neurological disease, the human brain has the capacity to store almost unlimited amounts of information indefinitely. Forgetting, therefore, is more likely to be result from incorrectly or incompletely encoded memories, and/or problems with the recall/retrieval process. It is a common experience that we may try to remember something one time and fail, but then remember that same item later. The information is therefore clearly still there in storage, but there may have been some kind of a mismatch between retrieval cues and the original encoding of the information. �Lost� memories recalled with the aid of psychotherapy or hypnosis are other examples supporting this idea, although it is difficult to be sure that such memories are real and not implanted by the treatment. Having said that, though, it seems unlikely that, as Richard Schiffrin and others have claimed, ALL memories are stored somewhere in the brain, and that it is only in the retrieval process that irrelevant details are �fast-‐forwarded� over or expurgated. It seems more likely that the memories which are stored are in some way edited and sorted, and that some of the more peripheral details are never stored. Forgetting, then, is perhaps better thought of as the temporary or permanent inability to retrieve a piece of information or a memory that had previously been recorded in the brain. Forgetting typically follows a logarithmic curve, so that information loss is quite rapid at the start, but becomes slower as time goes on. In particular, information that has been learned very well (e.g. names, facts, foreign-‐language vocabulary, etc), will usually be very resistant to forgetting, especially after the first three years. Unlike amnesia, forgetting is usually regarded as a normal phenomenon involving specific pieces of content, rather than relatively broad categories of memories or even entire segments of memory.



Theorists disagree over exactly what becomes of material that is forgotten. Some hold that long-‐term memories do actually decay and disappear completely over time; others hold that the memory trace remains intact as long as we live, but the bonds or cues that allow us to retrieve the trace become broken, due to changes in the organization of the neural network, new experiences, etc, in the same way as a misplaced book in a library is �lost� even though it still exists somewhere in the library. Increasing forgetfulness is a normal part of the ageing process, as the neurons in ageing brains lose their connections and start to die off, and, ultimately the brain shrinks and becomes less effective. The hippocampus, which as we have seen is crucial for memory and learning, is one of the first areas of the brain to deteriorate with age. Recent studies in mice involving infusions of blood from young mice into older mice have shown that the old mice that received young blood showed a significant burst of brain cell growth in the hippocampus region (and vice versa), leading to speculation that young blood might represent the antidote to senile forgetfulness (and other ravages of old age). Similar studies on humans with Alzheimers disease are currently in progress. Interestingly, it appears NOT to be possible to deliberately delete memories at will, which can have negative consequences, for example if we experience traumatic events we would actually prefer to forget. In fact, such memories tend to be imprinted even more strongly than normal due to their emotional content, although recent research involving the use of beta blockers (such as propanonol) suggests that it may be possible to tone down the emotional aspects of such memories, even if the memories themselves cannot be erased. The way this works is that the act of recalling stored memories makes them "malleable" once more, as they were during the initial encoding phase, and their re-‐storage can then be blocked by drugs which inhibit the proteins that enable the emotional memory to be re-‐saved. MEMORY RECALL/RETRIEVAL Recall or retrieval of memory refers to the subsequent re-‐accessing of events or information from the past, which have been previously encoded and stored in the brain. In common parlance, it is known as remembering. During recall, the brain "replays" a pattern of neural activity that was originally generated in response to a particular event, echoing the brain's perception of the real event. In fact, there is no real solid distinction between the act of remembering and the act of thinking. These replays are not quite identical to the original, though -‐ otherwise we would not know the difference between the genuine experience and the memory -‐ but are mixed with an awareness of the current situation. One corollary of this is that memories are not frozen in time, and new information and suggestions may become incorporated into old memories over time. Thus, remembering can be thought of as an act of creative reimagination. Because of the way memories are encoded and stored, memory recall is effectively an on-‐the-‐fly reconstruction of elements scattered throughout various areas of our brains. Memories are not stored in our brains like books on library shelves, or even as a collection of self-‐contained recordings or pictures or video clips, but may be better thought of as a kind of collage or a jigsaw puzzle, involving different elements stored in disparate parts of the brain linked together by associations and neural networks.



Memory retrieval therefore requires re-‐visiting the nerve pathways the brain formed when encoding the memory, and the strength of those pathways determines how quickly the memory can be recalled. Recall effectively returns a memory from long-‐term storage to short-‐term or working memory, where it can be accessed, in a kind of mirror image of the encoding process. It is then re-‐stored back in long-‐term memory, thus re-‐consolidating and strengthening it. The efficiency of human memory recall is astounding. Most of what we remember is by direct retrieval, where items of information are linked directly a question or cue, rather than by the kind of sequential scan a computer might use (which would require a systematic search through the entire contents of memory until a match is found). Other memories are retrieved quickly and efficiently by hierarchical inference, where a specific question is linked to a class or subset of information about which certain facts are known. Also, the brain is usually able to determine in advance whether there is any point in searching memory for a particular fact (e.g. it instantly recognizes a question like �What is Socrates� telephone number?� as absurd in that no search could ever produce an answer). There are two main methods of accessing memory: recognition and recall. Recognition is the association of an event or physical object with one previously experienced or encountered, and involves a process of comparison of information with memory, e.g. recognizing a known face, true/false or multiple choice questions, etc. Recognition is a largely unconscious process, and the brain even has a dedicated face-‐recognition area, which passes information directly through the limbic areas to generate a sense of familiarity, before linking up with the cortical path, where data about the person's movements and intentions are processed. Recall involves remembering a fact, event or object that is not currently physically present (in the sense of retrieving a representation, mental image or concept), and requires the direct uncovering of information from memory, e.g. remembering the name of a recognized person, fill-‐in the blank questions, etc. Recognition is usually considered to be �superior� to recall (in the sense of being more effective), in that it requires just a single process rather than two processes. Recognition requires only a simple familiarity decision, whereas a full recall of an item from memory requires a two-‐stage process (indeed, this is often referred to as the two-‐stage theory of memory) in which the search and retrieval of candidate items from memory is followed by a familiarity decision where the correct information is chosen from the candidates retrieved. Thus, recall involves actively reconstructing the information and requires the activation of all the neurons involved in the memory in question, whereas recognition only requires a relatively simple decision as to whether one thing among others has been encountered before. Sometimes, however, even if a part of an object initially activates only a part of the neural network concerned, recognition may then suffice to activate the entire network.



In the 1980s, Endel Tulving proposed an alternative to the two-‐stage theory, which he called the theory of encoding specificity. This theory states that memory utilizes information both from the specific memory trace as well as from the environment in which it is retrieved. Because of its focus on the retrieval environment or state, encoding specificity takes into account context cues, and it also has some advantages over the two-‐stage theory as it accounts for the fact that, in practice, recognition is not actually always superior to recall. Typically, recall is better when the environments are similar in both the learning (encoding) and recall phases, suggesting that context cues are important. In the same way, emotional material is remembered more reliably in moods that match the emotional content of these memories (e.g. happy people will remember more happy than sad information, whereas sad people will better remember sad than happy information). According to the levels-‐of-‐processing effect theory, another alternative theory of memory suggested by Fergus Craik and Robert Lockhart, memory recall of stimuli is also a function of the depth of mental processing, which is in turn determined by connections with pre-‐existing memory, time spent processing the stimulus, cognitive effort and sensory input mode. Thus, shallow processing (such as, typically, that based on sound or writing) leads to a relatively fragile memory trace that is susceptible to rapid decay, whereas deep processing (such as that based on semantics and meanings) results in a more durable memory trace. This theory suggests, then, that memory strength is continuously variable, as opposed to the earlier Atkinson-‐Shiffrin, or multi-‐store, memory model, which just involves a sequence of three discrete stages, from sensory to short-‐term to long-‐term memory. The evidence suggests that memory retrieval is a more or less automatic process. Thus, although distraction or divided attention at the time of recall tends to slow down the retrieval process to some extent, it typically has little to no effect on the accuracy of retrieved memories. Distraction at the time of encoding, on the other hand, can severely impair subsequent retrieval success. The efficiency of memory recall can be increased to some extent by making inferences from our personal stockpile of world knowledge, and by our use of schema (plural: schemata). A schema is an organized mental structure or framework of pre-‐conceived ideas about the world and how it works, which we can use to make realistic inferences and assumptions about how to interpret and process information. Thus, our everyday communication consists not just of words and their meanings, but also of what is left out and mutually understood (e.g. if someone says �it is 3 o�clock�, our knowledge of the world usually allows us to know automatically whether it is 3am or 3pm). Such schemata are also applied to recalled memories, so that we can often flesh out details of a memory from just a skeleton memory of a central event or object. However, the use of schemata may also lead to memory errors as assumed or expected associated events are added that did not actually occur.



There are three main types of recall: • Free recall is the process in which a person is given a list of items to remember and

then is asked to recall them in any order (hence the name �free�). This type of recall often displays evidence of either the primacy effect (when the person recalls items presented at the beginning of the list earlier and more often) or the recency effect (when the person recalls items presented at the end of the list earlier and more often), and also of the contiguity effect (the marked tendency for items from neighbouring positions in the list to be recalled successively).

• Cued recall is the process in which a person is given a list of items to remember and is then tested with the use of cues or guides. When cues are provided to a person, they tend to remember items on the list that they did not originally recall without a cue, and which were thought to be lost to memory. This can also take the form of stimulus-‐response recall, as when words, pictures and numbers are presented together in a pair, and the resulting associations between the two items cues the recall of the second item in the pair.

• Serial recall refers to our ability to recall items or events in the order in which they occurred, whether chronological events in our autobiographical memories, or the order of the different parts of a sentence (or phonemes in a word) in order to make sense of them. Serial recall in long-‐term memory appears to differ from serial recall in short-‐term memory, in that a sequence in long-‐term memory is represented in memory as a whole, rather than as a series of discrete items. Testing of serial recall by psychologists have yielded several general rules: o more recent events are more easily remembered in order (especially with auditory

stimuli);

o recall decreases as the length of the list or sequence increases; o there is a tendency to remember the correct items, but in the wrong order; o where errors are made, there is a tendency to respond with an item that resembles

the original item in some way (e.g. �dog� instead of �fog�, or perhaps an item physically close to the original item);

o repetition errors do occur, but they are relatively rare; o if an item is recalled earlier in the list than it should be, the missed item tends to be

inserted immediately after it; o if an item from a previous trial is recalled in a current trial, it is likely to be recalled at

its position from the original trial.



If we assume that the "purpose" of human memory is to use past events to guide future actions, then keeping a perfect and complete record of every past event is not necessarily a useful or efficient way of achieving this. So, in most people, some specific memories may be given up or converted into general knowledge (i.e. converted from episodic to semantic memories) as part of the ongoing recall/re-‐consolidation process, so that that we are able to generalize from experience. It is also possible that false memories (or at least wrongly interpreted memories) may be created during recall, and carried forward thereafter. Research into false memory creation is particularly associated with Elizabeth Loftus' work in the 1970s. Among many other experiments in this area (see the side panel on the Psychogenic Amnesia page, for example), she showed how the precise wording of a question about memories (e.g. "the car hit" or "the car smashed into") can dramatically influence the recall and re-‐creation of memories, and can even permanently change those memories for future recalls -‐ a phenomenon which is not lost on the legal profession. It is thought that it may even be possible, up to a point, to choose to forget, by blocking out unwanted memories during recall, a process achieved by frontal lobe activity, which inhibits the laying down or re-‐consolidation of a memory. However, there is a rare condition called hyperthymesia (also known as hypermnesia or superior autobiographical memory) in which a few people show an extraordinary capacity to recall detailed specific events from a person�s personal past, without relying on practised mnemonic strategies. Although only a handful of cases of hyperthymesia have ever been definitively confirmed, some of these cases are quite startling, such as a California woman who could recall every day in complete detail from the age of 14 onwards, a young English girl with an IQ of 191 who had a perfect photographic memory spanning almost 18 years, and a Russian man known simply as "S." who was only able to forget anything by a deliberate act of will. One of the most famous cases, known as �A.J.�, described it as a burden rather than a gift, but others seem to be able to organize and compartmentalize their prodigious memories and do not appear to feel that their brains are "cluttered" with excess information. There is a good "60 Minutes" documentary on the subject at http://www.cbsnews.com/video/watch/?id=7166313n. Interestingly, recent research has shown that such individuals tend to have significantly larger than average temporal lobes and caudate nuclei, and many exhibit mild Obsessive Compulsive Disorder-‐like behaviour (the caudate nucleus is also associated with OCD).



5. CHAPTER 6: MEMORY (DEWEY) (http://www.intropsych.com/ch06_memory/tofc_for_ch06_memory.html) Overview of Chapter 6: Memory Memory feels like a dip into the past, but actually memory takes place in the present moment. It uses information stored in the past and in some cases reconstructs events from the past. This is like baking a cake using a recipe. The result can be a reasonably good copy of what came before, or it can turn out to be totally different. Memory processes are creative processes, and memory errors are more common than most people think. Memory research is one of the oldest forms of experimental research in psychology, but it really blossomed in the 1960s and 1970s. During those decades memory research became a hot area. The so-‐called encoding revolution marked the end of stimulus-‐response inherited from mid-‐20th Century behaviorism and the beginning of the information processing approach that increasingly predominates in 21st Century experimental psychology. Biological theories came to the forefront with the emergence of the neurosciences in the 1980s and 1990s, and in the 21st Century large scale memory processes can be visualized in brain scans. In present-‐day psychology, memory is not regarded as a single process or a single system. It occurs in multiple systems operating in parallel. To some extent, each different system in the brain has its own memory. This contrasts with the assumption common during psychology's first century (1860-‐1960) that memory was a single system shared by different parts of the brain. Large-‐scale, integrated, event memories are now regarded as one important type of memory� but only one type. The topic of memory is one of practical importance. College students are confronted every day with the necessity of using their memory. Research on memory can help students understand why some study habits work, while others do little good. We will see (in "What Should a Student Do?") that repetition and effort, by themselves, have little effect on memory. Much more important is the cultivation of interest and attention to detail, plus a good night's sleep after studying. How this chapter is organized The first section starts with the oldest tradition of memory research, that of Ebbinghaus. We will examine Ebbinghaus's rationale for using nonsense syllables. We will see how the effort to remove meaning from memory research failed and how the "encoding revolution" in memory research focused new attention on the ways people manipulate information.



Next we examine the different types of memory documented by researchers in recent decades. Some examples are semantic memory, procedural memory, episodic memory, and implicit memory. The section titled "Biological Perspectives on Memory" examines research on the brain processes that influence memory. We will find that memory benefits from a little adrenaline...but not too much. A section on memory improvement examines other ways memory is enhanced. We review classic techniques such as mnemonic systems, then we address the question of how a student might best improve memory for academic material. Finally, we end the chapter with a look at people with fantastic memories of various types. Although each extraordinary memorist uses a different approach, one can find common elements in their techniques, and we try to draw some conclusions for ordinary people based on the unusually capable memories of these individuals. Related topics in other chapters V Chapter 3 (States of Consciousness) discusses hypnosis and memory. The Conditioning chapter (Chapter 5) discusses acquisition of classical and operant conditioned responses, a form of learning and memory. Memory turns up in Chapter 11 (Personality Theories) in Freud's concept of repression and in Chapter 13 (Therapies) in Adler's diagnostic use of early memories. Chapter 14 (Frontiers of Psychology) discusses eyewitness testimony and cryptomnesia in the context of Psychology and Law.



6. THE ATKINSON-‐SHIFFRIN MODEL (http://www.intropsych.com/ch06_memory/atkinson-‐shiffrin_model.html) Memory is not one thing. Rather, it is any process that allows us to use previously stored information in present cognitive constructions. Such processes may be widespread in the brain, and each major brain system may have its own form of memory. This insight occurred gradually to modern psychologists and represented a major shift of emphasis in memory research, as compared to the historical era of Ebbinghaus and other early memory researchers. By the mid to late 1960s, psychologists were starting to get comfortable with the idea of human information processing. By this they meant the mental processes involved in acquiring, organizing, and using knowledge and information of any type. In 1965 Atkinson and Shiffrin suggested that human memory was organized as an information processing system with three stages. The diagram is based on their classic 1968 article in The Psychology of Learning and Memory, Vol. 2. The diagram suggests that information from the environment first enters a sensory storage system, which Atkinson and Shiffrin called the sensory registers. Information in this system (the first box) is preserved for a brief period so the brain can process it. Next the information enters a second box or memory system, labeled short-‐term store This box represents ongoing activity of the brain: whatever you are thinking about at the present moment. In the 1890s William James called this primary memory. In the 1970s it was often called short-‐term memory (abbreviated STM). The most common label in the 2000s is working memory, although some researchers argue for a distinction between working memory and short-‐term memory, based on subtle distinctions.



7. CRITICISMS OF THE THREE-‐BOX MODEL (http://www.intropsych.com/ch06_memory/criticisms_of_the_classic_three-‐box_model.html) Like all influential models and theories, the Atkinson-‐Shiffrin model attracted many criticisms. Here are some of them. What were objections to the Atkinson-‐Shiffrin model? 1. The sensory stores are sensory systems, not memory systems as most people think of the term "memory." 2. The three-‐box model suggests that there is nothing in between short-‐term and long-‐term memory. However, evidence shows that information can reside somewhere between the extremes of active attention and long-‐term storage. Memories can be "warmed up" but outside of attention. In other words, intermediate levels of activation are possible. 3. The three-‐box model implies that there is just one short-‐term system and just one long-‐term system. In reality, there are many memory systems operating in parallel (for example, different systems for vision, language, and odor memory). Each has short-‐term and long-‐term operations. 4) The Atkinson-‐Shiffrin model does not give enough emphasis to unconscious processes. Unconscious activation is shown with a tentative, dotted arrow. Modern researchers find that unconscious and implicit forms of memory are more common than consciously directed memory processes. In short, the old Atkinson & Shiffrin has its limitations. However, it is still a useful scheme, in part because every researcher is familiar with it and uses it as a foil (a sort of negative reference point) for proposing new ways of looking at memory.



8. ICONIC MEMORY (http://www.intropsych.com/ch06_memory/iconic_memory.html) In the classic Atkinson & Shiffrin model, the first box is labeled sensory registers. These are more commonly called the sensory stores today. The sensory stores are like brief delay systems associated with each sense. They preserve the pattern of stimulation before it enters attention. The sensory stores are sensory systems, but they are also memory systems because they preserve information after the external stimulus is gone. Other names for the sensory stores are sensory buffers, or very short term stores. What does "icon" mean? What are characteristics of iconic memory? Iconic memory is the sensory store for vision. The term icon means form or image. Ulric Neisser (1967) proposed this label to convey the idea that iconic memory preserves an exact duplicate of the image falling on the retina. Iconic memory was first reported in the modern era by George Sperling (1963). Sperling tested subjects by flashing several rows of letters on a screen for a split second to see how many letters they could read after very short exposures. What is a tachistoscope? What did Sperling do? Sperling used a tachistoscope (pronounced tuh-‐KISS-‐tuh-‐scope), an instrument invented by Volkmann in 1859 to replace a then-‐current methodology of using electric sparks to produce brief visual exposures. The tachistoscope used a camera-‐like shutter to flash a picture onto a screen for a brief time measured in milliseconds (thousandths of a second). In Sperling's experiment, subjects saw an array of letters like this flashed very briefly on a screen:

W P X T M R C S L H Y D

Subjects were asked to read as many letters as possible during the brief flash. Usually they could only read 3 or 4 letters. Next Sperling tried a variation of his experiment called the partial report method. After he flashed the letters he sounded a high, medium, or low tone. Depending on which tone was sounded, the subject read the high, medium, or low row of letters. When was the tone sounded, in the "partial report" experiment? Because the tone came only after the flash of letters, you might think it would not do the subjects any good. However, Sperling found that as long as the tone was sounded within 250 milliseconds (a quarter second) of the flash, subjects could report 3 out of 4 letters from any row. Apparently they preserved a memory of the entire image for a quarter second.



What function does iconic memory serve? Why does this memory system exist? Eye movements take about a quarter second, and during a sudden eye movement, visual information from the eye to the brain is interrupted. During this quarter second, the iconic memory system preserves information from the last place where the eye stopped (the previous "eye fixation"). Therefore iconic memory helps maximize useful information available to the visual system, preserving information from one eye fixation while the eye moves to the next fixation point. When did Sperling's subjects think the tone was sounded? Partly because of iconic memory, we are unaware of the gap between eye fixations. Similarly, Sperling's subjects were unaware of the gap between the flash of letters and the tone. They simply waited for a tone and read the appropriate row. They believed the image of letters was still showing on the screen when the tone sounded. Actually they were reading the letters from their iconic image when the tone sounded. What is another "sensory storage" system for visual information, and how long does it last? The iconic image is complete. It contains all the sensory information available from the retina of the eye. However, it lasts only a fraction of a second and cannot be conjured up voluntarily at a later time. Probably the location of the iconic image is the circuitry of the retina itself. Complex experimental techniques reveal that individual sensory traces or "pictures" can also be preserved in visual processing areas of the brain for up to five minutes. Unlike iconic images, the image memories which last for several minutes are "accessible to higher level processes" such as attempts to remember a picture (Ishai and Sagi, 1995). This second system might be the one used by people with so-‐called photographic memory, called eidetikers, discussed later in this chapter.



9. ECHOIC MEMORY (http://www.intropsych.com/ch06_memory/echoic_memory.html) Just as the eye has a delay system to cling onto sensory information, so does the ear. The auditory information store, dubbed echoic memory by Neisser (1967), lasts one or two seconds. Echoic memory can also be called the auditory store or auditory sensory register. What is echoic memory and how long does it last? How did Guttman and Julesz test the duration of echoic memory and what did they determine? One creative experiment designed to measure echoic memory was carried out by Guttman and Julesz (1963). They used a computer to generate repeating segments of white noise. White noise is composed of all frequencies randomly mixed together. It sounds like "shhhh" and cannot be described or memorized. The computer made it possible to put together a repeating pattern of white noise with no gap between repetitions. The subjects had no clue that a sound was being repeated. Guttman and Julesz instructed subjects to put on headphones, listen to the noise, and report what they heard. If the repeating segment of white noise lasted longer than a few seconds, the subjects never realized it was repeating. They heard a continuous whooshing sound with no pattern. If the segment of white noise was less than two seconds long, the subjects suddenly realized they heard a repeated sound. They still could not describe the sound (other than saying "shhhh") but they knew it was being repeated. To detect a repeating pattern of random frequencies, subjects must use a memory system capable of preserving an exact copy of the noise from one repetition to the next. This is what echoic memory does: it preserves the exact pattern of sound for one or two seconds. How does the "Why did you say?" phenomenon illustrate echoic memory? A less scientific demonstration of echoic memory is the "What did you say?" phenomenon, which goes like this: Person #1: "What time is it?" Person #2: "What did you say? Oh, 2:30." The second person hears the question after asking, "What did you say?" This is due to echoic memory, which holds the sound of the question for a second or two. Even if you were not paying attention to the words when they were uttered, you can "hear" them when you turn your attention to them. This can be annoying to the person who starts repeating the question only to be interrupted by an answer. Development of brain scanning technology made it possible to observe echoic memory in the brain. Using MEG (magnetoencephalography),Lu, Williamson, and Kaufman (1992) were able to show activity in a portion of the auditory cortex (part of the cerebral cortex which responds to sound) lasting two to five seconds after a sound stimulus.



10. WORKING MEMORY (http://www.intropsych.com/ch06_memory/working_memory.html) Whatever information is held in attention at a given moment is said to be in working memory. This is the information you are "thinking about." Working memory is also called primary memory and short-‐term memory. What is working memory? What are its two components? Brain scans show that working memory involves two components: short-‐term storage that lasts only for a few seconds, and longer-‐term "executive processes that operate on the contents of storage" (Smith & Jonides, 1999). Zelinsky & Murphy (2000) describe the short-‐term process as a visual scratchpad which briefly preserves the visual appearance of a scene, while the longer-‐term process is a verbal storage system used when people rehearse or repeat something to themselves again and again to remember it. 11. REHEARSAL (http://www.intropsych.com/ch06_memory/rehearsal.html) Rehearsal is an example of an executive process in working memory. In other words, it is a consciously controlled form of information processing that people must learn; they do not do it automatically. When people are trying to remember an unfamiliar telephone number as they punch it into a phone, they typically repeat the number to themselves. This is what memory researchers call rehearsal. Several forms of evidence indicate that silent language rehearsal is much like re-‐hearing something. For one thing, silent rehearsal takes the same time as spoken speech (Landauer, 1962). Also, errors made during language rehearsal involve confusions between similar sounds as would happen with spoken speech. A subject might remember the nonsense syllable "DNW" as "TNW" because "D" and "T" both contain the "ee" sound. Sound-‐based errors presumably occur during rehearsal because the auditory image starts to fade and subjects grasp at the fading image to reconstruct it. Errors based on similar sounds are called acoustic confusions. What is evidence that rehearsal is like an internal voice? What are acoustic confusions? Why do they occur? A student provides this example: Recently, I experienced acoustic confusion. A friend of mine called and asked if I would like to come over. He gave me his room number, which was North 205, and I kept rehearsing it over and over in my head. By the time I reached Dorman Hall, I was saying North 209. I went to room 209, knocked on the door, and went in. I asked where Jeff was, and they said he was not in that room; he was in 205. I was really embarrassed, but when we studied about acoustic confusions during rehearsal I realized what I had done. [Author's files] This is an example of an acoustical error because "5" and "9" share the hard "i" sound. If the student was distracted while rehearsing the number "205," perhaps she grasped at the "i" sound and reconstructed the number as "209," all in a split second, without being aware of the error.



12. THE MAGICAL NUMBER SEVEN PLUS OR MINUS TWO (http://www.intropsych.com/ch06_memory/magical_number_seven.html) One of the best-‐documented characteristics of working memory is its limited capacity. The short-‐term storage process of working memory can hold only about seven items at a time. To deal with more information than that, the information must be organized into larger chunks. For example, words can be combined into sentences or stories; then more than seven words can be held in working memory. Psychologist George Miller pointed out the seven item limitation of working memory in a classic 1956 article, "The magical number seven, plus or minus two: Some limits on our capacity for processing information." As you can see from date, this journal article was published in the early days of the encoding revolution...in fact, some people say this article started the whole idea of using computer concepts like information processing to understand human memory. What is a chunk? The magic number seven is the number of chunks of information a person can hold in working memory at the same time. A chunk is a unit of some kind. It could be a letter, a word, or a short sentence. Think of it as a box or container in memory. Miller examined short-‐term memory tasks and found that typical subjects could hold about 7 chunks in memory at once. This was true whether the subjects were holding 7 letters in memory at once, 7 numbers at once, or 7 words at once. Miller wrote in a humorous tone that he was being "persecuted by an integer" (the number 7) in these studies. Old-‐time psychologists, before the encoding revolution, probably would have assumed that fewer words could be held in memory than letters, because each word contains many letters. But this is not the case. Miller's big discovery was that an organized whole (a chunk) functions as one item in primary memory. What was Miller's "big discovery?" Miller realized the profound implications of this simple insight. If items can be grouped and treated as chunks in memory, then the capacity of memory can be increased by organizing and grouping things. To demonstrate this to yourself, try holding the following sequence of numbers in memory, all at once. How can you reduce the string of 10 numbers to 4 chunks?

7 4 1 4 9 2 1 9 4 5

If you interpret this as a string of ten separate numbers, it exceeds the capacity of working memory. Ten chunks are too many to hold at one time in primary memory. But if you recognize two meaningful dates in the string of digits, you have only four chunks, and you easily hold the string of 10 digits in working memory.



Chunking points to the importance of organization in overcoming the limits of memory. If short term, working memory is limited to about 7 chunks, the only way to improve its capacity is to organize larger chunks. This turns out to be a common theme in memory research. Memory is improved by organizing little pieces into larger wholes.

How did Smith quadruple his memory capacity? In his original article, Miller described a 1954 experiment by psychologist Sidney Smith. Smith memorized sets of four binary digits, which are always 1s or 0s (e.g. 0 0 1 0). Each four-‐number set of binary numbers is equivalent to one decimal digit (0 0 1 0 equals the number 2). This meant that a string of 16 binary numbers could be converted into 4 decimal numbers. Once Smith learned to make the 4-‐to-‐1 conversion easily and automatically, his memory span for binary digits increased from 10 to about 40. In other words, he could memorize 10 decimal numbers in a row, then convert them back into 0's and 1's to reconstruct a list of 40 binary numbers. How did an undergraduate use recoding to improve his memory for digits, in an experiment lasting more than a year? Ericsson, Chase and Faloon (1980) decided to see how far this "recoding" idea could be pushed. They had an undergraduate student memorize random strings of decimal digits an hour a day, 3 to 5 days a week, for more than a year and a half. (Presumably they paid him well for this effort!) At the end of this period his memory span had increased from 7 to 79 digits. In other words, he could repeat back a string of 79 random digits immediately after hearing it without any error. His long-‐term memory for the digits also improved. By the end of the experiment, he often remembered many sequences from previous days. The subject was not instructed in any particular coding scheme; he invented his own. Being a runner, he found it easiest to translate number sequences into running times. The number 3492 was recoded as "3 minutes and 49 point 2 seconds, near world-‐record mile time." Later this was supplemented with ages; e.g. 893 became 89 point 3, very old man. (Ericsson, Chase & Faloon, 1980, p.1181). What sort of "burden" seems to improve, rather than harm, memory? This should remind you of example from Miller, Galanter, and Pribram described earlier, involving a subject who memorized "BOF" and "MIB" by composing a sentence about a man named BOF who was in "false misery" (MIB). There is an important principle lurking here: Human memory seems to work better, not worse, when a person adds elaborate encoding schemes, as long as they provide organization to aid memory retrieval.



13. VARIETIES OF SECONDARY MEMORY (http://www.intropsych.com/ch06_memory/varieties_of_secondary_memory.html) Atkinson and Shiffrin depicted long-‐term memory as one box in the mid-‐1960s. Since then, psychologists have found several different systems that contribute to secondary or long-‐term memory. The relevant distinctions are often conveyed in pairs of opposites: —episodic vs. semantic memory (memory for single events vs. information extracted from repeated events) —declarative vs. procedural memory (memory for facts vs. processes) —implicit vs. explicit (memory which is automatically retrieved vs. memory which requires a a conscious act of retrieval) These are distinct forms of memory. In some cases they are based in distinct biological systems within the brain. For example, procedural memory seems to require the cerebellum, the "small brain" at the back of the skull. Episodic memory seems to require the hippocampus and temporal lobes. Implicit memory is embedded in many brain systems and acts semi-‐independently, while explicit memory requires some coordination by the executive processes of the frontal lobes. What are different names for episodic memory? Consider the first distinction: between single events and repeated events. Memory researcher Endel Tulving (1972) coined the term episodic memory for memory of single episodes of your life. Episodic memory is sometimes called single-‐event memory because it is a memory for a distinct experience at a particular time and place. It can also be called autobiographical memory. It seems to have a tag on it that says, "This was an event in my life." Episodic memory can be entirely wiped out by brain damage to the hippocampal/temporal lobe area. Clive Wearing is a famous patient who lost his event memory after an infection of the brain. He does not remember a moment of his life, before or after the encephalitis. As soon as information leaves his working memory, it is forgotten, and he always feels like he is "just waking up" or "just becoming conscious for the first time." What happens in cases of dissociative amnesia? Episodic memory can also be lost independently of other forms of memory in certain cases of dissociative amnesia. Dissociative amnesia is the classic amnesia syndrome seen in old-‐time movies. Some people who experience a psychological trauma react by forgetting who they are. They forget personal information—memory linked to their identity. In other words, they lose episodic memory. However, they retain memory for factual knowledge. Such a person could tell you that 2+2 equals 4. The same is true of Clive Waring, who has disattached knowledge like the fact that England returned Hong Kong to the Chinese (something that happened after his brain damage). Clive's problem, being due to brain damage, is irreversible. Most episodes of dissociative amnesia caused by psychological trauma are reversible.



Why has the name "semantic memory" gone out of favor with some psychologists? Knowledge like "2 + 2 = 4" or "Hong Kong is part of China" is encountered repeatedly. This distinguishes such knowledge from personal event knowledge, which represents a unique and one-‐time event. Tulving's term for non-‐episodic memory, semantic memory, has gone out of favor with some psychologists, because "semantic" means "related to word meanings" and this type of memory involves more than words. Therefore researchers now distinguish between memory for single events (episodic memory, which requires the brain area called the hippocampus) and memory for general knowledge abstracted from repeated events (declarative and procedural memory, which require other brain areas). What problem did N.T. have? Tulving studied a patient known as N.T. who, like Clive Waring, lost all his episodic memory. In N.T.'s case, the damage was caused by a stroke. N.T. was capable of learning new word meanings, skills, and facts. He lost only his memory for the individual events of his life. Note that non-‐episodic memory in this case involved both skills (procedural memory) and facts (declarative memory) 14. DECLARATIVE VS. PROCEDURAL MEMORY (http://www.intropsych.com/ch06_memory/declarative_vs._procedural_memory.html) Declarative memory is is memory for repeatedly encountered facts and data such as who is president, what is the square root of 25, and where you were born.

Procedural memory, by contrast, is specifically memory for sequences of events, processes, and routines. Deciding which letter of the alphabet has three vertical strokes (M) involves declarative memory. Remembering how to tie your shoes, ride a bike, or shoot a layup on a basketball court requires procedural memory.

What are two types of memory for general knowledge? What is evidence they are distinct systems?

Evidence for a basic distinction between declarative knowledge and procedural knowledge comes from the effects of brain damage and electric shock. In the 21st Century ECS (electroconvulsive shock) procedures are refined to the point where "shock treatments" do not produce measurable effects on memory, largely because of drugs that are administered before treatment and have a protective effect on brain tissue. However, in earlier decades, the treatment was cruder, and memory loss after ECS was common. Patients receiving electroconvulsive shock treatments (ECS) often showed amnesia for factual information presented to them in the preceding days. They showed no similar loss of memory for procedural skills that they practiced before the shock.



15. IMPLICIT VS. EXPLICIT MEMORY (http://www.intropsych.com/ch06_memory/implicit_vs_explicit_memory.html) Certain forms of memory do not require conscious executive control. An example is remembering how to brush your teeth. You probably do not need to think about it. These forms of memory—called implicit memory —are usable even if a person suffers severe brain damage from organic brain syndromes such as Alzheimer's Syndrome. What is the difference between implicit and explicit memory? People who are drunk, or who suffer from organic brain syndromes, may perform very poorly on memory tasks requiring conscious control: explicit memory tasks. An example of an explicit memory task would be reciting everything you remember reading on the last page. By contrast, implicit memory tasks are automatic responses, drawn out or elicited by a situation, like clapping after a performance. In the following columns, tasks on the left are examples of implicit memory that do not require executive control. Brain-‐damaged or intoxicated humans can still perform them. Tasks on the right are examples of explicit memory that do require some conscious control. They are performed poorly by people who are brain-‐damaged or drunk.

Tasks requiring implicit memory Tasks requiring explicit memory mirror tracing recalling last year reading reversed text paired associate learning doing a word-‐completion task identifying the head of state singing part of a familiar song writing a term paper

Items in the left column are all indirect forms of memory. They do not involve a conscious strategy for retrieving information. If you once learned to read text that is printed backwards, chances are you will be able to do it later, even if you suffer a brain disorder. The same is true of the other tasks on the left. How does implicit memory help old people who stay in their own homes? The importance and power of implicit memory helps explain why old people are often more comfortable and capable when they stay in a familiar place. Years of living in the same rooms produces implicit memory such as knowing where to find a broom and other useful knowledge and skills. When an old person is put in a nursing home or other unfamiliar environment, the same person may seem disabled, because none of the old automatic routines work in the new environment. What was discovered in the study of "alcohol amnesia? Hashtroudi, Parker, DeLisi, Wyatt, and Mutter (1984) studied the effects of alcohol on implicit and explicit memory. Ninety-‐six male volunteers between the ages of 21 and 35 were recruited for the all-‐day experiment (they were kept at the lab until their blood alcohol returned to zero). The researchers found that alcohol intoxication had effects similar to brain injury. It damaged explicit memory but not implicit memory.



The subjects were divided into 6 groups of 16. Three groups received alcoholic drinks; three groups received placebos. Each received 4 drinks in 40 minutes, then the memory tests began. Subjects saw a list of words for 2 seconds each. They performed an arithmetic task for 5 minutes, then they were tested on one of three memory tests: (1) recalling the words, (2) recognizing the words, (3) identifying the words in degraded form.

Degraded words progressively filled in What tasks were affected by alcohol, and what were not? The figure shows some degraded words used in the experiment. Each subject had to indicate as quickly as possible the word seen a few minutes earlier for 2 seconds. First they saw the word in severely degraded form (top) then with more and more of the word revealed.(as shown top to bottom). Alcohol-‐intoxicated subjects performed just as well as sober subjects on the last two tasks: recognizing the degraded words and recognizing other words in a Yes/No recognition test. (Actually the drunk subjects identified fewer words from the list, but they also made fewer errors of false identification, so the recognition scores came out the same.) Both forms of recognition are examples of implicit memory, because a person does not have to perform any elaborate or deliberate mental activity to recognize a word. You see the word, later on you recognize it, and it is all somewhat automatic and effortless. However, on the recall task, a big difference appeared. Drunk subjects recalled only half as many words as sober subjects. This was a task that involved explicit memory. Subjects knew they would be asked to recall the words later, so they probably tried to memorize them during the initial presentation of the list. Sober subjects were better at this consciously controlled process.



With what type of memory are preschool children just as good as adults? Implicit memory occurs under the surface all the time. As you explore the environment, you absorb information about it continuously without trying. If somebody asks you where a certain missing object is located, you may reply, "Oh, I saw that in such-‐and-‐such a place." You did not make a conscious effort to memorize its location when you saw it, nor did you have to make much of a conscious effort to retrieve this information when the person asked you about it. Implicit memory operates almost without conscious intervention. No sophisticated executive control is required. That is why preschool children are sometimes as good as adults at tasks requiring only implicit memory. Ask a 3 year old where a favorite toy is, and the child is as likely as you are to remember where it was last seen. Ask a 3 year old to hold a series of numbers in memory and he or she will not perform well, because a child does not know to rehearse such a series to "hold it in memory." This is something learned, and it requires executive control. What did Crowder say about implicit memory? Implicit memory is very pervasive or widespread in human cognitive processing. Robert G. Crowder of Yale University pointed out, "Most researchers now agree that implicit memory is more influential than explicit, conscious memory" (Bower, 1990). 16. PRIMING (http://www.intropsych.com/ch06_memory/priming.html)



A technique called priming can demonstrate implicit memory. A person who sees the word yellow will be slightly faster to recognize the word banana as a word. This happens because the words yellow and banana are closely associated in memory. What is "priming"? What is a "semantic network"? Researchers sometimes envision a network of word meanings or semantic network somewhat like the diagram. The distance between words indicates the frequency with which the words are associated in everyday life. Because of these associations, activating one node of the network (showing the person one word) warms up or primes nearby words, speeding retrieval. This effect lasts about 30 minutes after exposure to the priming word. Are priming effects implicit or explicit? Why? Priming does not require conscious rehearsal of word meanings. The associations between words used in a priming experiment are not consciously memorized for purposes of the experiment; they are naturally occurring associations. (However, they are learned, and they can be culture-‐specific. Not every society has yellow school busses, for example.) No conscious strategy is required to show priming effects. Brain-‐damaged and intoxicated people show the same priming effects as other people. This is another example of implicit memory. Indeed, the example used on the preceding page, about implicit vs. explicit memory, was also a form of priming. It involved degraded words, shown as a cue to recall words a person saw earlier in the experiment. In that case, the experimenters were interested in seeing whether the priming effect (showing the words earlier) would occur equally in drunk and sober subjects, which it did. How does priming normally help language comprehension? In normal reading, words seen ahead of the fixation point of the eye (in peripheral vision) are activated in semantic memory ("warmed up") so when the eye fixates upon them, their meanings are available faster. Similarly, in conversation, if you hear somebody say, "I ate a yellow" [followed by a muffled word that sounds like "an-‐an-‐an"] you might well hear "I ate a yellow banana" because you have a semantic network like the one in the diagram. The word banana is activated by its association to the word yellow, so you easily retrieve it even if the stimulus is partial or degraded. The memory retrieval is automatic, evoked by the situation, so this is an example of implicit memory.



17. SUMMARY: DIFFERENT TYPES OF MEMORY (http://www.intropsych.com/ch06_memory/summary_different_types_of_memory.html) One of the earliest theories of memory during the information processing era was the Atkinson and Shiffrin model. It portrayed memory as a flow of information through three boxes, each representing a distinct memory system. The first box consisted of the sensory stores. The sensory storage system for vision is called iconic memory. George Sperling showed that a visual image persists for a split second after stimulation. The sensory storage system for hearing is called echoic memory. Studies indicate that it lasts for about two seconds. Other senses such as taste have split-‐second memory systems, too. The second box in the classic Atkinson-‐Shiffrin model represents the short-‐term store also known as primary memory, working memory, and short-‐term memory. Working memory has two components: a short-‐lasting visual "scratchpad" and a longer-‐lasting verbal memory. The longer-‐lasting verbal memory enables you to circulate words in your head. Rehearsal is one way to keep information in primary memory; you just say something to yourself again and again. The verbal portion of working memory has a limited capacity. George Miller coined the term "chunk" to describe an organized entity or thing in memory. Working memory can handle about seven chunks at one time. To increase the amount of information in attention, one must increase the amount of information in each chunk. This can be done by organizing material into integrated wholes, each of which functions as one chunk. Secondary memory, also known as long-‐term memory, comes in several distinct varieties. Memory for general knowledge is apparently stored differently from memory for personal events of one's life. There are at least two types of general knowledge derived from repeated experiences: declarative knowledge and procedural knowledge. Memory for factual information is stored differently from memory for procedures. Memory that requires conscious processing (explicit memory) is easier to disrupt than automatic (implicit) memory.

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EDS 103 Module 3.3 Information Processing Theories- … · Module!3.3!COGNITIVE!THEORIES!!!!! "Experiential,Learning,Theories"!! Site:! University!of!the!Philippines!Open!University:!!