Chapter 1
Introduction to Cognitive Psychology
The Complexity of Cognition
• Cognition involves
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Perception
Attention
Memory
Representation of knowledge
Language
Problem-solving
Reasoning and decision-making
• All include “hidden” processes of which we may
not be aware
Some Questions to Consider
• How is cognitive psychology relevant to
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everyday experience?
Are there practical applications of cognitive
psychology?
How is it possible to study the inner workings
of the mind when we can’t really see the mind
directly?
What is the connection between computers
and the study of the mind?
The First Cognitive Psychologists
• Donders (1868)
– Mental chronometry
• Measuring how long a
cognitive process takes
– Reaction-time (RT)
experiment
• Measures interval
between stimulus
presentation and
person’s response to
stimulus
The First Cognitive Psychologists
• Donders (1868)
– Simple RT task: participant pushes a
button quickly after a light appears
– Choice RT task: participant pushes one
button if light is on right side, another if
light is on left side
Caption: A modern version of Donders’ (1868) reaction-time
experiment: (a) the simple reaction-time task; and (b) the choice
reaction-time task.
The First Cognitive Psychologists
• Donders (1868)
– Choice RT – Simple RT = Time to make a
decision
• Choice RT = 1/10th sec longer than
Simple RT
• 1/10th sec to make decision
The First Cognitive Psychologists
• Donders (1868)
– Mental responses cannot be measured
directly but can be inferred from the
participant’s behavior
The First Cognitive Psychologists
• Helmholtz (~1860s)
– Unconscious inference
• Some of our perceptions are
the result of unconscious
assumptions we make about
the environment
– We infer much of what we
know about the world
The First Cognitive Psychologists
• Ebbinghaus (1885)
– Read list of nonsense syllables aloud many
times to determine number of repetitions
necessary to repeat list without errors
The First Cognitive Psychologists
• Ebbinghaus (1885)
– After some time, he relearned the list
• Short intervals = fewer repetitions to
relearn
– Learned many different lists at many
different retention intervals
The First Cognitive Psychologists
• Ebbinghaus (1885)
– Savings =
[(initial repetitions) – (relearning repetitions)] /
(initial repetitions)
– Forgetting curve shows savings as a function
of retention interval
Caption: Ebbinghaus’s retention curve, determined by the method of
savings. (Based on data from Ebbinghaus, 1885.)
The First Cognitive Psychologists
• Wundt (1897)
– First psychology
laboratory
– University of
Leipzig, Germany
– RT experiments
The First Cognitive Psychologists
• Wundt (1897)
– Approach
Structuralism: experience is determined
by combining elements of experience
called sensations
– Method
Analytic introspection: participants
trained to describe experiences and
thought processes in response to stimuli
The First Cognitive Psychologists
• John Watson noted two
problems with this:
– Extremely variable
results from person to
person
– Results difficult to verify
• Invisible inner mental
processes
The Rise of Behaviorism
• John Watson proposed a new approach
called behaviorism
– Eliminate the mind as a topic of study
– Instead, study directly observable behavior
The Rise of Behaviorism
• Watson (1920) – “Little Albert” experiment
– Classical conditioning of fear
– 9-month-old became frightened by a rat
after a loud noise was paired with every
presentation of the rat
Classical Conditioning
• Pair a neutral event with an event that
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naturally produces some outcome
After many pairings, the “neutral” event
now also produces the outcome
Pavlov’s Discovery: Classical Conditioning
Caption: Pavlov’s famous experiment paired ringing a bell with presentation of
food. Initially, only presentation of the food caused the dog to salivate, but after a
number of pairings of bell and food, the bell alone caused salivation. This principle
of learning by pairing, which came to be called classical conditioning, was the basis
of Watson’s “Little Albert” experiment.
The Rise of Behaviorism
• Watson (1920) – “Little Albert” experiment
– Behavior can be analyzed without any
reference to the mind
– Examined how pairing one stimulus with
another affected behavior
The Rise of Behaviorism
• Skinner (1950s)
– Interested in determining the relationship
between stimuli and response
– Operant conditioning
• Shape behavior by rewards or
punishments
• Behavior that is rewarded is more likely
to be repeated
• Behavior that is punished is less likely to
be repeated
Caption: Timeline showing early experiments studying the mind in the
1800s and events associated with the rise of behaviorism in the 1900s
The Decline of Behaviorism
• A controversy over language acquisition
• Skinner (1957)
– Argued children learn language through
operant conditioning
• Children imitate speech they hear
• Correct speech is rewarded
The Decline of Behaviorism
• Chomsky (1959)
– Argued children do not only learn language
through imitation and reinforcement
• Children say things they have never
heard and can not be imitating
• Children say things that are incorrect and
have not been rewarded for
– Language must be determined by inborn
biological program
The Decline of Behaviorism
• The Misbehavior of Organisms (1961)
– Attempts to condition animal behavior did
not work
– Animals’ built-in instincts prevailed
The Decline of Behaviorism
• Tolman (1938) trained rats to find food in a
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four-armed maze
Two competing interpretations:
– Behaviorism predicts that the rats learned
to “turn right to find food”
– Tolman believed that the rats had created
a cognitive map of the maze and were
navigating to a specific arm
The Decline of Behaviorism
• Tolman (1938)
• What happens when the rats are placed in a
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different arm of the maze?
The rats navigated to the specific arm where
they previously found food
– Supported Tolman’s interpretation
– Did not support behaviorism interpretation
Caption: Maze used by Tolman. (a) Rat initially explores the maze; (b) then learns
to turn right to obtain food at B when it starts at A; (c) when placed at C, the rat turns
left to reach the food at B. In this experiment, precautions are taken to prevent the rat
from knowing where the food is based on cues such as smell.
Studying the Mind
• To understand complex cognitive behaviors:
– Measure observable behavior
– Make inferences about underlying
cognitive activity
– Consider what this behavior says about
how the mind works
The Cognitive Revolution
• Shift from behaviorist’s stimulus-response
relationships to an approach that attempts to
explain behavior in terms of the mind
The Cognitive Revolution
• Information-processing approach
– A way to study the mind created from
insights associated with the digital
computer
Caption: (a) Flow diagram for an early computer. (b) Flow
diagram for Broadbent’s filter model of attention.
The Cognitive Revolution
• Early computers (1950s)
– Processed information in stages
• How much information can the mind
absorb?
• Attend to just some of the incoming
information?
The Cognitive Revolution
• Cherry (1953)
• Dichotic listening
– Present message A in left ear
– Present message B in right ear
– To ensure attention, shadow one message
• Participants were able to focus only on the
message they were shadowing
The Cognitive Revolution
• Broadbent (1958)
– Flow diagram representing what happens
as a person directs attention to one
stimulus
– Unattended information does not pass
through the filter
FIG 1.12
Caption: Timeline showing events associated with the decline of
the influence of behaviorism (above the line) and events that
led to the development of the information-processing approach
to cognitive psychology (below the line).
Researching the Mind
• Behavior approach measures relationship
between stimuli and behavior
• Physiological approach measures
relationship between physiology and behavior
• Both contribute to our understanding of
cognition
Researching the Mind – Memory
Consolidation
• Memory for recent events is fragile
• If processing is disrupted, recent memories
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can fail to be consolidated
New information can interfere with memory
consolidation
Researching the Mind – Memory
Consolidation
• Behavior approach
• Muller and Pilzecker (1900) had participants
learn two lists of words
– Independent variable:
• One group learned the second list immediately
after the first list
• The other group experienced a six-minute
delay between learning the lists
– Dependent variable:
• Memory (recall) for the first list of words
Researching the Mind – Memory
Consolidation
• Behavior Approach
• Gais et al. (2007) the effect of sleep on
memory consolidation
– Independent variable:
• One group learned a list of words shortly before
going to sleep
• The other group, many hours before going to
sleep
– Dependent variable:
• Memory (forgetting) for the list of words
measured two days later
Caption: Results of the Gais et al. (2007) experiment in which
memory for word pairs was tested for two groups. The sleep
group went to sleep shortly after learning a list of word pairs.
The awake group stayed awake for quite a while after learning
the word pairs. Both groups did get to sleep before testing, so
they were equally rested before being tested, but the
performance of the sleep group was better.
Researching the Mind – Memory
Consolidation
• Physiological approach
• Gais et al. (2007) the effect of sleep on
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memory consolidation
– Brain activity at encoding and retrieval
– Measured using brain imaging (fMRI)
Results
– Found differential brain activity between
the two groups
Cognitive Science
• Interdisciplinary study of the mind
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– Psychology
– Computer science
– Cognitive anthropology
– Linguistics
– Neuroscience
– Philosophy
Goal: finding ways to study and understand
the inner workings of the mind