Cognitive PsychologyEXP 3604Ira Fischler

• Welcome to the course

• CP in the curriculum

• Web resources

– www.psych.ufl.edu/~fischler

• Course structure and requirements

• CP in science and society

• Scope and nature of CP

CognitivePsychology

A COGNITIVE PSYCHOLOGIST’SVIEW OF THE ACADEMIC WORLD

social psychology

neuropsychology

developmentalpsychology

anthropologyneuroscience

education

humanities and arts

philosophy

computer science

sports & music

evolutionarypsychology

WHAT IS COGNITIVE PSYCHOLOGY?

• BY FORMAL DEFINITION– the study of human mental processes and

their role in perception, attention, memory, thinking and decision-making (Goldstein)

• BY TOPIC– attention and information processing

– memory: representation and dynamics

– Language and concepts

– thinking and problem solving

• BY ISSUES– does “subliminal learning” work?

– What is the matter in dyslexia?

– Do you use the cell phone and drive?

– are “recovered memories” reliable?

– What is insight? Intuition? Creativity?

– Should you get a smallpox vaccination?

– Can we increase IQ by training?

GOALS OF COGNITIVE PSYCHOLOGY

• PERFORMANCE– how accurate? ..fast? ..much?

• PROCESS– models of the stages and codes

involved in a cognitive task

• PRINCIPLES– what is the “functional organization

of the mind?”

to describe human cognition in terms of

COGNITIVE PSYCHOLOGYCourse Goals

• THE COGNITIVE APPROACH– how to think about cognition like a

cognitive psychologist

• THE METHODS OF THAT APPROACH– understanding the interplay between

theoretical and experimental tools

• THE NATURE AND LIMITS OF COGNITION– how we do those things we do

(e.g., perceive, attend, recall, think…)

• TIPS AND TECHNIQUES FOR ENHANCING COGNITION– methods of improving your skills in

learning, remembering and thinking

In EXP 3604, you will learn about...

… and revive that childlike sense of awe

A CAPSULE HISTORY OFCOGNITIVE PSYCHOLOGY

• A VIEW OF PROGRESS IN SCIENCE– Thomas Kuhn (1962): THE STRUCTURE

OF SCIENTIFIC REVOLUTIONS– Normal science versus “Paradigm shifts”

– Revolutions in the natural sciences– Revolutions in the social sciences– Progress or “cultural construct”?

• PHILOSOPHICAL INQUIRY– since 500 BC: From Greece to the

Enlightenment• Plato: innate, ideal “concepts”

(nativism) and knowledge via reason (rationalism)

• Aristotle: the role of experience in learning, and observation in science (empiricism)

• Kant: innate concepts of space, time and causality; cognitive “schema”

• Locke and the British Empiricist tradition

SCIENTIFIC PSYCHOLOGY IS BORN1850’s: Psychophysics (e.g., Fechner)1880’s: Introspection (e.g., Wundt)

• REACTIONS TO INTROSPECTION’S..– Elementalism: vs. “global” aspects of

perception > Gestalt Theory (Kohler)

– Accessibility: vs. “imageless thought” > Psychoanalysis (Freud)

– Structuralism: vs. the “purposiveness” of cognition > Functionalism (James)

– Scientific validity: vs. problemswith replication & bias >Behaviorism (Watson)

• THE COGNITIVE REVOLUTION– 1950s: Information processing

(e.g., Broadbent)

COGNITIVE PSYCHOLOGY IS BORN (1950 - 1965)

• BEHAVIORISM EVOLVES– e.g., Lawrence (1952)

• HUMAN FACTORS– e.g., Broadbent (1955)

• INFORMATION THEORY– e.g., Shannon (1949)

• LINGUISTICS– e.g., Chomsky (1957)

• COMPUTER SCIENCE– e.g., von Neumann (1950)

COGNITIVE PSYCHOLOGY - e.g., Neisser (1967)

THE INFORMATION-PROCESSING FRAMEWORK

• STAGES OF PROCESSING– The sequence of mental operations that

occur as we do a task

• how many stages?• do they require attention?• are they obligatory?• do any stages occur “in parallel”?

• CODES OF REPRESENTATION– The form or nature of the information

being processed

• visual or verbal?• analog or conceptual?

Broadbent’s“structural”IP model (1955):

MEMORY STRUCTURES AND PROCESSES IN

THE “MODAL MODEL”(Atkinson & Shiffrin, 1968)

SENSORY REGISTERSsensoryinputs

SHORT-TERM STORE (STS)temporary, working memory

LONG-TERM STORE (LTS)

permanent memory store

visual auditory

control processes: - rehearsal - coding - decisions - retrieval strategies

tactile

USING REACTION TIME TO STUDY PROCESSING STAGES

Letter-matching: Same or Different?(Posner & Mitchell, 1967)

AA, ff, LL etc… “yes” msec

Aa, Gg, kK etc… “yes” msec

Ad, gF, RM etc… “no” msec

Type of Pair Response RT

Aa requires one additional stage, soAa - AA gives the time of that stage

This difference correlates withverbal SAT scores! (Hunt, 1975)

STAGES AND CODES IN ASIMPLE PROCESSING TASK

Letter-matching: Same or Different?(Posner & Mitchell’s “task” IP model, 1967)

(stimulus appears)

Select response left key right key

Aa

See the letters

Compare the forms same form?

YESNOName the letters

Compare the names

YESNOsame names?

STRATEGIES OF COGNITIVE NEUROSCIENCE

• The Coin of the Realm: correlations between psychological and neurophysiological events/structures

• Establishing two-way constraints between levels– Cognitive psychology as the bootstrap– Neuroactivity as the bootstrap

• Regions of interest (ROI’s) and localization of function– Subtractive versus parametric designs– Event-related activation “dynamics”

• Covariation and functional networks– Patterns of correlated activity among

multiple regions of interest

EEG and EVENT-RELATED POTENTIALS (ERPs)

• Postsynaptic extracellular potentials vary with neuronal activity

• Masses of pyramidal cells generate a varying electrical signal, the EEG

• Changes in the EEG that are related to psychological events (ERPs) can be seen by averaging

• Various ERP “components” are sensitive to cognitive processes

MAGNETOENCEPHALOGRAPHY

• methodology– Incredibly weak magnetic signal

(femtoTeslas)– Detected by SQUID ($3M, 16,000 lbs,

minus 269 deg C– Works for neural fields tangental to

surface

MAGENTIC RESONANCE IMAGING (MRI)

• Align the spins of Water-based hydrogen atoms by powerful magnetic field

• Create a “gradient” in the field• “pulse” the field with

a strong radio-frequency signal thatperturbs the alignment

• Using an RF detector, track the return to alignment

• With really complex computing, reconstruct the 3D density of tissue in the brain

FUNCTIONAL MAGNETIC RESONANCE IMAGING

(fMRI)

• Oxygenated blood has different magnetic properties than deoxy

• So comparing MRI between target task and “control” task (a challenge) reveals areas of task-related activation

fMRI (cont’d)

• Event-related fMRI allows tracking of the “hemodynamic response” to individual events:

Source: Kwong et al., 1992

COLLECTING EEG

REACTION TIME AND UNCERTAINTY (Hick, 1952)

300

320

340

360

380

400

420

440

1 2 3 4 5 6 7 8# of possible "targets"

Reaction Time to Begin Movementto one of N targets

Rea

ctio

n T

ime

(mse

c)

A logarithmic function – as predictedBy Shannon’s Information Theory (1949)

Davachi, Lila et al. (2003)Meaning, Brain activity, and Memory

Davachi, et al. (2003)Increases in activation

for Image vs. Read

Davachi, et al. (2003)Difference in activation

(Image – Read)for Remember vs. Forget