Cognition Study of how the mind works. Study of basic mental functions of the mind. Includes a variety of mental process: perception, pattern recognition, language, etc.

Cognition Equals

Cognitive Psychology Theoretical orientation emphasizing mental structures and processes and breaks them down into component structures and processes How sensory information is acquired, stored, transformed and used. Mental activity or acquisition, storage, transformation, and use of knowledge

Neisser’s Defintion of Cognitive Psychology “Cognitive Psychology refers to all processes by which the sensory input is transformed, reduced elaborated, stored, recovered, and used.”

Levels of Cognition Perception Attention Pattern Recognition Memory Organization of Knowledge Language Reasoning Problem Solving Decision Making

Codes System of signals used to represent something -- e.g. code for the alphabet Neural Code: e.g. the word ‘hat’ encoded as a pattern of light on the retina Cognitive Code: the word ‘hat’ --> phonemes (language sounds), letters, meaning

Level of Description Mental Level Cognitive Level Neural Level

Question Answer this question as quickly as you can: How many hands did Aristotle have?

Cognitive Process Analysis

Cognitive Psycholgy Development Timeline

Thinking as a Sequence of States

Wilhelm Wundt “ Conscious processes and immediate experience” Introspection or “self observation” Rigorous Methods

Titchener Structuralism Training of observers Imageless thought controversy

Herman Ebbinghaus Study higher mental processes using scientific method Process of association formation Non-sense syllables Savings Method

Nonsense Syllables DAX GIK TEB KOV SUV HET

Ebbinghaus’ Method - Learn list to 2 perfect recitations (# trials) Set aside (varied delay) Relearn (# trials) Measurement of Savings Ebbinhaus constructed more than 2000 of these syllables and studied his own learning. Used this method to exam forgetting as a function of: Time between two sessions Degree of learning or overlearning Type of material (e.g. nonsense syllables vs. poetry) Acclaimed. Had invented a reasonably scientific, enduring method to study memory and mental processes. Started the Verbal Learning Tradition--became an important part of Cognitive psychology. # Trials to Learn - # Trials to Relearn

Measurement of Savings # Trials to Learn - # Trials to Relearn

Forgetting Curve

William James

William James - Functionalism Interested in the functions of consciousness Infer mental mechanisms or processes from the way organisms behave in different situations. Functions of Memory Primary Memory Secondary Memory

20th Century

Behaviorism John B. Watson (1924) Reaction to Introspection Emphasis on observable, quantifiable behavior No unobservables, no internal mental states, no images, ideas, or thoughts

Behaviorism Psychology = Scientific study of behavior Humans as passive reactors to external stimuli “Tabular Rasa” - Environmental determinants of behavior Rats in mazes, puzzle boxes, etc.

Behaviorism - Positive Contributions Insistence of precise & careful definition of concepts Operational Construct e.g. performance = # trials necessary to complete a maze with no errors Experimental Control

Gestalt Psychology Laws of organization Law of proximity Law of similarity Insight problem solving

Law of Similarity O O O O X X X X

Law of Proximity O O O O X X X X

Frederick C. Bartlett Remembering: An Experimental and Social Study (1932) Meaningful materials -- e.g. stories Human memory constructive process Original material interpreted and transformed

The Cognitive Revolution Return to mentalistic ideas (1940’s and 50’s) MIT – Sept. 11, 1956 Neisser’s book Cognitive Psychology (1967) Information processing perspective Diverse Influences/ Causes

Stimulus-Response

Dissatisfaction with Behaviorism Challenges to “tabular rasa” Innate structure or knowledge Complex human behavior not explainable in terms of stimulus-response relations alone

World War II

World War II Practical Problems Problems of perception, judgement, thinking, and decision-making Operating technical equipment Performance over Learning Human Factors

Information Processing

Verbal Learning Flourishing of Ebbinghaus tradition Different types of memory, memory organization, models Active nature of learner--what is brought to learning Formation of new associations --> Use of pre-existing associations. Emphasis on Memory over learning

Bousfield (1953) apple desk bicycle couch shirt chair banana car socks desk peach truck couch orange train hat desk couch chair peach apple hat shirt dress … Etc. Words presented in this order: But recalled In this order

Verbal Learning … Existing memory associations lead to reorganization of words during recall Mental Processes: rehearsal, storage, organization, retrieval Acceptance of objective methods & procedures But increased commitment to inferred processes -- e.g. encoding, storage, retrieval

Noam Chomsky

Linguistics Rejection of behaviorist notions of language Emphasis on mental processes underlying language learning Novelty of utterances 2 Major Claims Language knowledge innate Grammatical rules/system

Evidence Same age of acquisition Similar stages and length of time to acquire Limited # of Grammars Novel utterances Evidence for rule use: Irregular past tense verbs

Evidence for Rule Use: Irregular past tense formation Initially ‘go’ --> ‘went’ ‘eat’ --> ‘ate’ Later (after acquiring regular past tense rule) ‘go’ --> ‘goed’ ‘eat’ --> ‘eated’

Telephone example “UD has improved the appearance of the university over the last few years.”

Communications Theory Information processing idea Similarity between communication devices and people 1st approximation analogy for psychology to describe mental processes Channel, information processing filters, limited capacity, serial vs. parallel processing.

Information Theory Information Source Transmitter Channel Receiver Destination

Computers & Computer Science Numerous contributions Analogy of computers & humans Both process information: Take in information, transform, manipulate, store, & output information (or some type of product--e.g. behavior) Humans & computers as symbol manipulators

Schematic Diagram of Computer System

Atkinson & Shiffrin Memory Model

Many Contributions Borrowing of concepts & characteristics of computers to describe human system: sensory store, short-term store, long-term store Limited capacity--immediate memory & attention

Additional Contributions Computer programs/processes analagous to mental processes Simulation modeling AI Computer as tool Modeling Stimulus Presentation

Current Issues Related to Cognitive Psychology Ecological Validity Cognitive Science Cognitive Neuroscience Artificial Intelligence Parallel Distributed Processing Approach

Cognitive Neuroscience Examines how the structure & function of the brain explain cognitive processes Kossylyn’s Message Complexity Necessity of cognitive/functional analyses New Tools/Techniques

Cognitive Neuroscience Techniques Brain Lessions Brain Imaging Techniques PET MRI fMRI Event-related Potential Single-cell Recording Technique

PET Scan

Pet Scan 2 PET Scan while listening to a language task (unpracticed) PET Scan after practice with the task (spelling)

Event-related Potentials

An ERP Recording

Artificial Intelligence Machine Metaphor Artificial Intelligence (Pure AI) Computer Simulation

PDP - Parallel Distributed Processing Cognitive processes can be understood in terms of networks of ‘neuron-like’ units Connectionism vs. neural networks Parallel vs. Serial Distinction

Matlin’s 5 Themes Cognitive processes are active Cognitive processes remarkably efficient & accurate Cognitive processes handle positive information better than negative Cognitive processes are Interrelated Many cognitive processes rely on both bottom-up and top-down processing

What do you see?

Context Effects