What is Cognitive Psychology?

1. 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.

2. “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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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)

12. 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

13. 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

14. 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

15. 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

16. Info. Processing model Short-term / Working Memory Sensory Memory Overt Response Behavior Environmental Stimuli Long-term Memory & Knowledge Cognitive Psychology is concerned with what goes on in here.

17. 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!

18. Sternberg Paradigm • Test of how info is processed • Subjects (Ss) memorize list of digits • {4, 6, 5, 9, 3, 2} • Given recognition test • 9? • Yes/No • Measure both accuracy and reaction time (Msec.) • Some trials were false (8?) • Some were true (9?)

19. Think in terms of Memory system! STM / WM LTM - 4 - 6 9 - 5 + 9 - 3 - 2 Decision

20. Results

21. 6, 9, 3, 2 9? Perceive Stimulus 9=3? 9=2? Make decision Generate response 9=6? 9=9? 7? Perceive Stimulus Make decision Generate response 7=6? 7=9? 7=3? 7=2? 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?

22. 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