Memory

Psychology: A Concise Introduction

2nd Edition

Richard Griggs

Chapter 5

Prepared byJ. W. Taylor V

The Journey…

Three-Stage Model of Memory

Encoding Information into Memory

Retrieving Information from Memory

Three-Stage Model of Memory

Encoding Information into Memory

Retrieving Information from Memory

Three-Stage Model of Memory

Sensory Memory

Short-Term Memory

Long-Term Memory

The Three-Stage Model

Has guided research in memory since the late 1960s

Views memory as composed of three relatively distinct stages

SensorySensory Short-TermShort-Term Long-TermLong-Term

The Three-Stage Model

Sensory Memory

Consists of a set of five registers (temporary storage places, one from each sense) for incoming sensory information from the physical environment until we attend to it, interpret it, and it proceeds to the next stage of memory (short-term memory)

Iconic Memory

Is an exact copy of visual information Less than a second in duration Very large capacity

Consider the example of a cartoon movie, which is nothing more than a series of still drawings flashed in rapid succession Iconic memory allows us to

perceive motion in the drawings

Testing Iconic Memory

The temporal integration procedure involves giving two random meaningless dot patterns sequentially at the same visual location with a brief time delay between the two presentations When the two patterns

are integrated, a meaningful pattern is produced

An Example of the Temporal Integration Procedure

Testing Iconic Memory

For a meaningful pattern to be perceived, the two patterns must be integrated somewhere in the memory system However, if the time delay between the two

presentations is greater than one second, no meaningful pattern can be perceived because the image from the first pattern has faded from iconic memory

Testing Iconic Memory

Sperling’s full- and partial-report procedures present participants with a different 3 x 3 matrix of unrelated consonants (a total of 9) for 50 ms across numerous experimental trials

Here is an example:L Z Q

R B P

S K N

L Z Q

R B P

S K N

Testing Iconic Memory

In the full-report procedure participants had to report the entire matrix Participants said they sensed the entire matrix but

that it had faded from memory before they could report all 9 letters

Testing Iconic Memory

In the partial-report procedure, the participants had to report only one row of the matrix, a row indicated by an auditory cue on each trial When the auditory cue was given

immediately after the brief presentation of the letter matrix, participants recalled the indicated row 100% of the time

When there was a one second delay between presentation of the matrix and the auditory cue, participants’ recall of the cued row worsened

Short-Term Memory Is the memory stage in which the recognized informa-

tion from sensory memory enters consciousness It is where you are doing your present conscious

cognitive processing

Serves as a place to rehearse information so it can be transferred to long-term memory and as a place to bring information from long-term memory when asked to recall it Must concentrate on information in

short-term memory or it will be lost in 30 seconds

Capacity of Short-Term Memory

The memory span task tests for the capacity of short-term memory by giving a series of items one at a time The person has to remember the items in the order in which they

were presented Memory span is the average number of items you can

remember across a series of memory span trials Humans have a memory span of

7+/- 2 (5 to 9) chunks of information A chunk is a meaningful

unit of information Experts in a given domain tend

to have larger chunks for information in their area of expertise

Duration of Short-Term Memory

Measured using the distractor task, in which people are given a small amount of information (e.g., three unrelated consonants such as CWZ) Then the participant is immediately distracted from

concentrating on the information for a brief time period (by counting backwards aloud by 3’s), and then asked to recall the information

To keep information in short-term memory, we use maintenance rehearsal (i.e., repeating information in short-term memory to keep in from fading from short-term memory)

Results for the Short-Term Memory Distractor Task

Long-Term Memory

Allows storage of information for a long period of time (perhaps permanently) and its capacity is essentially unlimited

Types of Long-Term Memory

Explicit memory (also called declarative memory) is long-term memory for factual knowledge and personal experiences and requires conscious recall

Two types of explicit memories: Semantic memories are memories for factual

knowledge that is true of everyone (e.g., the current President of the United States)

Episodic memories are memories for personal life experiences (e.g., your senior prom night)

Types of Long-Term Memory

Implicit memory (also called non-declarative memory) is long-term memory that influences our behavior, but does not require conscious awareness or declarative statements (e.g., for most adults, driving a car; walking)

Some implicit memories are procedural memories because they have a physical procedural aspect to them

For a tennis expert, such as Serena Williams, the movements to play the game are implicit, procedural memories, whereas for the average person, such movements require conscious recall, and are more semantic memories

Other implicit memories have become automatic responses to certain stimuli (e.g., feeling tense when police car lights are flashing behind us)

Types of Long-Term Memory

Amnesia, the Loss of Long-Term Memories

Amnesics are people with severe memory deficits following brain surgery or injury

H. M. had his hippocampus and surrounding temporal lobe area removed at age 27 (to reduce epileptic seizures) Before the operation, both his short- and long-term memories were

normal After the operation, he didn’t seem to be able to store any new

information in long-term memory H.M. suffered from anterograde amnesia – the inability to form

long-term memories for events following brain surgery or trauma

By contrast, retrograde amnesia is the inability to remember events before, especially just before, the surgery or trauma

Infantile Amnesia

The cerebellum seems to be important for formation of implicit memories, whereas the hippocampus seems to be important for formation of explicit memories

Because the hippocampus does not fully develop until about the age of 3, this explains why we cannot remember as adults events that occurred prior to this age (i.e., infantile/ child amnesia)

Evidence for the Short-Termvs. Long-Term Distinction

H. M.’s short-term memory did not suffer any substantial damage after the operation

The free recall task is an experimental procedure in which participants are given a list of words one at a time, then asked to recall them in any order they wish Compared with the middle of such lists, the recall

of the items at the start of the list is superior (the primacy effect)

Compared with the middle of such lists, the recall of the items at the end of the list is superior (the recency effect)

Serial Position Effects for the Free Recall Task

Evidence for the Short-Termvs. Long-Term Distinction

The recency effect is caused by recall from short-term memory, whereas the primacy effect is the result of superior recall from long-term memory of the first few words in the list The first few words enter an empty long-term memory and get

proportionately more attention than the words in the middle of the list and can thus be transferred into long-term memory

The last few words are still in short-term memory at the time of recall

If recall is delayed by having participants count rapidly backward by 3’s for 30 seconds, the recency effect is eliminated, but the primacy effect remains

To eliminate the primacy effect, simply rehearse each of the items on the list equally

Encoding Information into Memory

How We Encode Information

How to Improve Encoding

Memory System Processes

EncodingThe process of

transferring information from

one memory stage to the next

EncodingThe process of

transferring information from

one memory stage to the next

Storage The process of

maintaining information in a

particular stage

Storage The process of

maintaining information in a

particular stage

RetrievalThe process of bringing stored

information from long-term

memory to the conscious level

in short-term memory

RetrievalThe process of bringing stored

information from long-term

memory to the conscious level

in short-term memory

How We Encode Information

Automatic processing is processing that occurs subconsciously and does not require attention

Effortful processing is processing that occurs consciously and requires attention

For a particular type of processing, much practice is needed

Levels-of-Processing Theory

Describes what types of encoding lead to better retrieval

Three levels of processing Physical: How information

appears Acoustic: How the information sounds Semantic: What the information means

Long-term memory is best for information encoded semantically, next best for information encoded acoustically, and worst of information encoded physically

Elaborative Rehearsal

Rehearsing information by relating new information to information already in long-term memory Contrasts with maintenance rehearsal (i.e., the repetitive cycling of information in

short-term memory) Elaborative rehearsal provides more retrieval cues to facilitate retrieval

A good way to elaborate on new material is to relate the material to yourself The self-reference effect says it is easier to remember information that you have

related to yourself because such connections provide more retrieval cues and lend more meaning to the new information

Environmental Effects on Encoding

Encoding specificity principle proposed that the cues present during encoding serve as the best cues for retrieval This is why the various concepts and examples

that you relate to a new concept during elaborative rehearsal help you remember the concept

State-dependent memory is memory that depends upon the relationship of one’s physiological state at the time of encoding and at the time of retrieval

Environmental Effects on Encoding

Mood-dependent memory effects attest to the fact that memory is better when a person’s mood is the same during encoding and retrieval For example, if you are happy during encoding information, it

is easier to retrieve that information if you are happy at the time of retrieval

Mood-congruence effect is the fact that memory is better for experiences that are congruent with a person’s current mood For example, when we are sad it is easier to retrieve

negative events in our lives

How to Improve Encoding

Mnemonics are memory aids that require elaborative rehearsal

In the method of loci, the sequential pieces of information to be remembered are first associated with sequential locations in a very familiar room or location When retrieving the information, you merely

mentally go around the room (or location) and retrieve the item stored at each sequential location; uses elaborative mental imagery

In the peg-word system, you visually associate the items to be remembered in a jingle that you first memorize

The Peg-Word Method

Term Keyword Meaning Mental Picture

Medulla Medal Controls heart rate, respiration, and blood pressure

Imagine the winner of a race (i.e., heart pounding and breathing heavily), while a medal is hung round the winner’s neck.

Pituitary glands

Pit Regulates growth

Imagine a young child down in a pit. The child grows and grows until he’s finally big enough to climb out!

The Peg-Word Method

Term Keyword Meaning Mental Picture

Para-sympa-thetic nervous system

Para-chute

Calms the body

Imagine the peace and calming effect of watching a parachute drift slowly downward.

Sympa-thetic nervous system

Sym-phony

Excites the body

Imagine a symphony playing loudly in the room next door! The music excites you and you can’t sit still.

The Peg-Word Method

Term Keyword Meaning Mental Picture

Reticular formation

Retickle Attention Imagine tickling someone to get her attention. Then, she loses interest so you have to retickle her!

Cere-bellum

Cereal bell

Facilitates movement

Imagine hearing the cereal bell. That’s the signal to move to the table and begin spooning cereal.

Other Tips for Improving Encoding

The spacing effect (or distributed study effect) contends that your memory will improve if you study for an exam over an extended time interval rather than just a few days before the exam

Overlearning is studying material past the point of initial learning, and has been demonstrated to aid in retrieval of that information

Retrieving Information from Memory

How to Measure Retrieval

Why We Forget

The Reconstructive Nature of Retrieval

How to Measure Retrieval

Recall is a measure of retrieval that requires the reproduction of the information with essentially no retrieval cues

Recognition is a measure of retrieval that only requires the identification of the information in the presence of retrieval cues

Relearning, also called the savings method, is a measure of the amount of time saved when learning the information for a second time

An Early Study

Ebbinhaus conducted the first experimental studies on human memory more than 100 years ago using the relearning method.

He would study a list of nonsense syllables until he could correctly recite the complete list without any hesitations. He then put the list aside and waited some period of time and then relearned the list to the same criterion.

To get a measure of learning, he computed a savings score – the reduction in the number of trials it took him to reach criterion.

Result? The “forgetting curve” reveals that most forgetting occurs in the first two days after learning material.

Forgetting Curve for Long-Term Memory

Why We Forget

Encoding failure theory says that sometimes forgetting is not really forgetting, but rather that the information never entered long-term memory in the first place

Storage decay theory suggests that forgetting occurs because of a problem in the storage of the information The biological trace of the memory gradually decays over

time and the periodic usage of the information will help to maintain it in storage

An Example of Encoding Failure

Why We Forget

Cue-dependent theory says we forget because the cues necessary for retrieval are not available The information is in memory, but we

cannot access it This theory is analogous to knowing a book

is in the library but you cannot access it because the library lacks call numbers

Interference theory proposes that other similar information interferes and makes the forgotten information inaccessible

Types of Interference

Proactive interference occurs when information you already know makes it hard to retrieve newly learned information

Retroactive interference occurs when information you just learned makes it hard to retrieve old information

Types of Interference

Types of Interference

Think about changing phone numbers after having a certain number for many years. When asked for your new phone number, remembering the old one interferes with retrieving the new one. This is proactive interference

Now think about being at a party with many people you don’t know. You meet someone whom you want to talk to later, but after meeting her, you are introduced to many more people. Now, you cannot remember her name. This is retroactive interference

The Reconstructive Nature of Retrieval

When reading a newspaper article, for instance, we usually code the gist or main theme of the story, along with some of the some of the story’s highlights Then, when we retrieve the information from our memory,

we re-construct a memory of the story using the theme and highlights

Retrieval re-construction is guided by schemas – organized frameworks of knowledge about people, objects, and events that tell us what normally happens in a given situation They allow us to encode and retrieve information more

efficiently

The Reconstructive Nature of Retrieval

Schemas, however, can lead us to “misremember” information so that it is more consistent with our schemas Frederick Bartlett (1932) had people read

unusual stories and subsequently recall details from the stories

When the participants recalled the stories, they made them more consist with their schemas about the world

Source Misattribution

Occurs when we do not remember the true source of a memory and attribute the memory to the wrong source

Source misattribution results in false memories, which are inaccurate memories that feel as real as accurate memories.

False memories can also occur because of the misinformation effect, which occurs when a memory is distorted by subsequent exposure to misleading information

A Study of False Memories

Loftus and Palmer (1974) showed people film of a traffic accident and later tested their memory for the accident

Some people were asked “How fast were the cars going when they smashed into each other?” and others were asked “How fast were the cars going when they hit each other?”

Participants asked the first question estimated a higher speed at impact and reported seeing broken glass when in fact there was none

Memory and Testimony

False memories suggest that eyewitness testimony is subject to error and manipulated by misleading information

Likewise, false memories suggest that recovered memories are not necessarily accurate