Psyc 317 001: Cognitive Psychology

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Psyc 317 001 Cognitive Psychology

• James Thompson, PhD
• Assistant Professor
• Psychology

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How to Contact Me

• Email jthompsz_at_gmu.edu
• Telephone [phone]

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Outline

• History
• The first cognitive psychologists
• The rise (and fall) of behaviorism
• The rise of the new cognitive psychology

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History Back in the day

• Aristotle
• 384-322 BC
• Tabula rasa (blank slate)
• Structure of the mind already in place?

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Fast forward to the 1860s

• Franciscus Donders - measured the speed of
  thought
• 1868
• Reaction time experiments

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What is reaction time?

• The time elapsed between some stimulus and the
  persons response
• Typically measured in milliseconds
• Considered a measure of difficulty

Space Bar
Time (ms)
Persons Reaction Time
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Donders Subtraction
Simple reaction time See light, press button
Choice reaction time See light, which button?
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Measuring the speed of thought
Simple Reaction Time experiment
Stimulus The light
Mind Sees light
Response Press button
Choice Reaction Time experiment

Stimulus The light
Mind Sees light
Response Press button
Mind Which button?
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Measuring the speed of thought
Example
Choice Reaction Time experiment 500 ms
-
Simple Reaction Time experiment 350 ms
150 ms
150 ms for the extra stage in choice RT 150 ms
to choose which button to press
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What does this tell us?

• Specifically
• How long it takes for the mind to choose a
  response

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What does this tell us?

• Generally
• Mental responses cannot be measured directly
• Must infer mental processing through behavior
• Behavioral measures
• Reaction times
• Accuracy/error rates

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Discussion time!

• Has anyone thought of a potential flaw in this
  logic?
• Clue Imagine cooking something and inserting a
  new step. What happens to the final recipe?
• The assumption of pure insertion

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Hemholtzs UnconsciousInference (1860s)
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What does this tell us?

• Specifically
• How does our mind recognize objects that are
  occluded by other objects?
• Some kind of automatic filling-in process
• Object recognition well talk about this in a
  few weeks

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What does this tell us?

• Generally
• Some of our perceptions are the result of
  automatic processes beyond our control
• Like reading the Stroop task
• Cognitive psychology can help to unmask the
  automatic processes

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Foundations of cognition

• These early researchers developed some basic
  principles
• Donders Mental processes must be inferred from
  behavior
• Hemholtz Mental processes are automatic and
  often unseen

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Willhelm Wundt

• 1832-1920
• First experimental psychology laboratory (Europe)
• Leipzig, Germany 1879

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Edward Titchener

• 1867-1927
• Born in England
• Studied in Germany under Wundt

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Structuralism (Wundt and Titchener)

• The study of the structure of the conscious mind
• Focus on the sensations, images, and feelings
  that are elements of consciousness

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Conscious structure of an apple

• Red
• Cold
• Crisp
• Sweet

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Wundts Introspection

• How to study the mind?
• Introspection Self-observation
• Subjects looks carefully inward and report on
  inner situations and experiences
• Example Describe the experience of hearing a
  5-note chord on the piano
• Hear one sound or individual notes?

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Wundts introspection criteria

• The subject must know when the experience begins
  and ends
• Subject is master of situation
• The subject must maintain "strained attention
• Mind does not wander

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Problems with structuralism

• Observers were highly trained, but self-reports
  were not consistent across people
• How can psychologists draw clear conclusions when
  introspection produces such varied data?

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Outline

• Introductions
• Syllabus
• What cognitive psychology is
• History
• The first cognitive psychologists
• The rise (and fall) of behaviorism
• The rise of the new cognitive psychology

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Behaviorism

• A response to Wundts introspection
• The scientific study of observable behavior only
• Behaviorism is antimentalistic
• Since mental processes cant be seen, they have
  no place in psychology
• Explanations like classical conditioning

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John B. Watson

• 1878-1958
• Professor of psychology
• Founder of behaviorism

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B.F. Skinner

• 1904-1990
• Professor of psychology
• Behaviorism
• Operant conditioning
• Positive and negative reinforcements

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Classical conditioning
If Unconditioned Stimulus ? Unconditioned
Response (meat powder) (salivation) then
pair Conditioned stimulus with the unconditioned
stimulus (tone) (meat powder) then
eventually Conditioned stimulus ? conditioned
response (tone) (salivation)
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Operant conditioning
It is possible for the animal to generate a
response and for that response to have
consequences
Act cute --gt Get pet
Poop on rug --gt Get scolded
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Cracks in the behaviorist framework

• 1960s Criticisms of behaviorism
• Behaviorism could not explain some phenomenon
• Critical periods/early learning
• Language
• Inability to override instinctual behavior

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Problems with behaviorism Critical periods

• Critical period A time when an animal is able to
  learn particular information rapidly and with
  little exposure
• If the time window is missed, the animal learns
  with greater effort or not at all

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Critical periods example

• Some birds follow the first large thing that they
  see when they are hatched - usually first large
  thing is mom
• The tendency to follow the first large thing has
  a critical period
• What happens if the first large thing is not mom?

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Critical periods Lorenz as mom
Behaviorism cannot explain critical periods!
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Problems with behaviorism Language

• The behaviorist account of language (Skinner,
  1957)
• Children learn language through imitation and
  reinforcement. Appropriate speech is rewarded.

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Criticism of behaviorist account of language

• The response (Chomsky, 1959)
• Behaviorist accounts ignore that language is
  generative. This means that virtually everything
  you say and hear is novel. It cant be the case
  that you understand it because of reinforcement
  in the past, because youve never heard it
  before.

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Evidence that for non-behaviorist view of language

• Generativity of language (production of novel
  sentences)
• Overextension of grammar
• I hitted the ball.
• This is never spoken by adults

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Problems with behaviorism Instinct/Fixed Actions

• The Misbehavior of Organisms (Breland Breland,
  1961)
• Try to train raccoon to put two coins in a piggy
  bank
• Raccoon would instinctively rub coins together,
  like they would with shellfish
• No amount of reward would cause extinction of the
  rubbing response

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Outline

• Introductions
• Syllabus
• What cognitive psychology is
• History
• The first cognitive psychologists
• The rise (and fall) of behaviorism
• The rise of the new cognitive psychology

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The rise of something new

• Information processing approach
• The mind processes information as it comes into
  the brain
• Rebirth of cognitive psychology parallels
  development of computers

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Cognition and Computation

• COGNITION
• Perception
• Attention
• Memory
• Problem solving
• Reasoning
• Decision making

• COMPUTATION
• Input from many sources
• Processing (memory, software)
• Output to many sources

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Allen Newell and Herbert Simon

• 1927-1992
• Computer science artificial Intelligence

• 1916-2001
• Economics mathematics
• Nobel Prize in economics for decision making

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The mind as computer?
Computer hardware diagram
Can we apply boxes and arrows to the mind?
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Early IP experiment attention

• Example Cherrys (1953) attention experiments
• String of words presented to each ear
• Subjects attend to one ear only
• Unattended stream is not remembered

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The mind as computer?
Block diagram of mental processes
(Flow diagram of how attention works)