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What is Cognitive Psychology?. Broad Definition –empirical investigation of mental events and knowledge involved in recognizing an object, remembering a name, having an idea, understanding a sentence, and solving a problem - PowerPoint PPT Presentation
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What is Cognitive Psychology?
• Broad Definition –empirical investigation of mental events and knowledge involved in recognizing an object, remembering a name, having an idea, understanding a sentence, and solving a problem
• Specific Definition - the empirical investigation of mental processes and activities used in perceiving, remembering, and thinking, and the act of using those processes.
• “Pay attention!” – Concept: Attention -- how we filter or select important information
from the environment.
• “I don’t know.”– Concept: Knowledge -- the store of general information and
algorithms for performing tasks.
• “I don’t remember.”– Concept: Memory -- a process for storing, retrieving and working
with information.
• “I can’t decide.”– Concept: Decision making – set of higher-level processes that
work together allow us function day to day
History of Cognitive Psychology
• Early history – Philosophical roots– Socrates – interested in the origins of
knowledge
– Aristotle – interested in origins of knowledge & memory
• Proposed first theory of memory
– Descartes – how is knowledge represented mentally
History of
• Recent history – Psychological roots– Wilhelm Wundt (1879)
• First psychological laboratory in Leipzig, GE– Founder of psychology as a science
– Many early psychologists had roots in Wundts lab
» Produced over 200 Ph.D students in philosophy and psychology
• Topic: Human cognition– Used introspection to report contents of consciousness
History of
– Edward Titchner• Student of Wundts, taught at Cornell University in
1892– Proponent of introspection– Narrow view of psychology
» Excluded mental illness, education apps., and social psych, b/c not open to introspection
» Note: Method defined what was allowable science– Founder of Structuralism
» Study of: Sensations, images, and feelings that were elements of the mind
– Often argued with Wundt over findings
History of
– Herman von Ebbinghaus• Contemporary of Wundt in GE
– Big influence on cognitive psych.
– Developed method for studying forgetting as function of time
» Stimuli: lists of Consonant-Vowel-Consonant’s (CVC’s)
» Method: Learn list of CVC’s, count number of trials to recall perfectly Wait 2 days re-learn list.
» Savings score = # of trials to learn the 1st time - # of trials to learn 2nd time
– One subject entire career – himself
– Learned over 40,000 CVC’s
History of
– William James• Wundt’s student, hired at Harvard
– Philosopher, but started first American psych. lab
• Proposed Functionalism– Stressed the functions over the mind rather than contents
» How does mind adapt to new circumstances?» Proposed multicomponent memory system: Primary
Memory vs. Secondary memory– Authored: Principles of Psychology, chapters on
Sensation, perception, attention, consciousness, memory, reasoning
History of
• Modern History– Human Performance (WWII)
• Attention and perception, – training of solders to use radio and radar
• Signal detection– Blips on radar or sonar
• Information theory – – abstract method for analyzing information processing
History of
– Artificial intelligence• How can we make computers behave intelligently?
• Contributed host of concepts– Idea of study machine, allowed us to study our own
processes
– Linguistics• Interested language and language development
• Contributed new mode of analyzing structure of language
Emergence of Cognitive Psychology
• 1950’s – 1970’s, no agreed upon date• Ulric Neisser’s “Cognitive Psychology” text
published in 1967• Why did Cog. Psyc emerge?
– Two major factors• Dissatisfaction w/ behaviorism’s account of complex behavior
(e.g., Chompsky’s new model of language)
• Convergence of several other fields during WWII– Linguistics, Human performance, AI
Contributors to Cog. Psych
• Human Performance– Abstract way to analyze processing of info.
(development of psychological tools!)– Research ideas in attention and perceptions
• AI– Idea of computer as info. Processor– Computer model – Tool for studying cognition– Focus on complex processing (decision making,
reasoning)
Contributors to Cog. Psych
• Linguistics & Verbal learning– Questions about language and its complexity
– Reason to reject behaviorism• Complexities of lang. Not handled by behaviorism
• Philosophy– Age old questions about knowledge and Memory
• Behaviorism– Strong empirical methods and laboratory research
Summary• Cog. Psych began with Wundt
– Cognitive issues of mental states– But, introspection method not strong
• Replication difficult, methodology determined acceptable sub-disciplines
• These problems fueled behaviorist movement
• Behaviorism was major paradigm from 1910’s to 1960’s– Focus shifted to overt behavior
• Stimulus response• Mind considered a black box, can’t study what you can’t see,
hear, feel, or touch
– Psychologists need reason to abandon behaviorism• Linguistic’s criticisms provided the stimulus
Summary• War time efforts - scientists from different fields
came together for one purpose– Focus on attention and perception– Expansion of methodological toolboxes
• Enabled Psychologist to go beyond S-R psych.
– Idea of humans as “Active” info. Processors• Contrast with behaviorism – Organisms respond to environment
• Invention of computer & focus on mental processes• Chompsky’s review of Skinner’s book on language
– Illuminated inadequacies of behaviorism
Cognitive Psychology
• Information processing approach – decomposition of mental processes– Multi-component memory system
• Assumptions of Cog. Psych.– Mental processes exist– People are active information processors– Mental processes and structures can be revealed
by time and accuracy measures
EnvironmentalStimuli
SensoryMemory
Short-term / WorkingMemory
Long-term Memory&
KnowledgeCognitive
Psychologyis concerned with
what goes on in here.
Overt ResponseBehavior
Info. Processing model
Component of Model
• Sensory memory – input device– What info is sent to the processor
• Short-term / Working memory– Central processor, actively processes info
• Long-term memory / Knowledge– Library of programs, algorithms, data, and
experiences that are stored for use†Note similarities to computer!
Sternberg Paradigm
• Test of how info is processed • Subjects (Ss) memorize list of digits
{4, 6, 5, 9, 3, 2}
• Given recognition test9?
Yes/No
• Measure both accuracy and reaction time (Msec.)Some trials were false (8?)
Some were true (9?)
Think in terms of Memory system!
96
5
9
3
2
4LTMSTM / WM
--
+-
--
Decision
Results
350
400
450
500
550
600
650
0 2 4 6 8
String size
Mse
c
Perceive Stimulus
Generate response
Make decision
9=9? 9=3?
9=6? 9=2?
Perceive Stimulus
Generate response
Make decision
7=9? 7=3?7=6? 7=2?
6, 9, 3, 2
9?
7?
What would happen if the search string were 6 items?
What would happen if degraded the probe?
What would happen if we biased the decision process?
• Time to respond was linear function of size of search string– Each element added 38 msec to search time
• Serial position did not matter!– Thus, search is exhaustive
• Sternberg’s conclusion: Ss engaged in serial matching process