Transcript Neobehaviorists

Neobehaviorists
Neobehaviorism
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Life after Watson
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Optimism
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But….
Neobehaviorists
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Influence by Watson?....Clearly.
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Hull
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Tolman
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Skinner
Clark Hull
Hull (1884-1952)
Ph.D from University of Wisconsin in 1918
Invited to Yale in 1929
President of APA in 1935
Hull –Early Interests
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University of Wisconsin
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Books:
Aptitude Testing (1928)
 Hypnosis and Suggestibility (1933)
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32 papers
Hull’s System - Yale
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Stimuli and responses are assumed to be
bridged by intervening variables such as:
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Drive
Fatigue
Habit strength
Incentive
Hull’s System
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Example:
SE R
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= SHR x D x V x K
E refers to action potential in a given situation
H refers to habit strength (or number of previous trials in the
situation)
D is drive strength (e.g., the number of hours of deprivation)
V refers to stimulus intensity
K refers to incentive motivation
Hull’s Theory
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Reinforcement:
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Played a key role
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Law of reinforcement:
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Stimuli that reduce drive stimuli are reinforcing.
Secondary reinforcement
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Any stimulus consistently associated with primary
reinforcers takes on reinforcing properties.
Hull - Legacy
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Central figure in the development of
quantitative approaches to behavior.
Principles of Behavior (1943)
A Behavior System (1952)
Edward C. Tolman
Tolman (1886-1959)
Graduates with B.S. from MIT (1911)
Harvard (1915) – Ph.D in Psychology
President APA (1937)
Tolman’s System
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Great range of topics that we encounter in our
daily lives
Focus on the role of cognition and purpose
Wanted a psychology with true breadth of
perspective that retained the desirable objective
features of classical behaviorism.
Tolman’s System
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Believed that psychological processes intervene
between stimuli and responses.
Intervening variables:
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Cognitions
Expectancies
Purposes
Hypotheses
Appetite
Example:
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Expectancies:
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Develops when a reward follows each
successful response.
Then becomes involved in directing and
controlling behavior
Tolman - Reinforcement
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A reinforcer (e.g., food) has nothing to do
with learning, as such, but do regulate the
performance of learned responses.
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Learning vs. Reinforcement vs. Performance
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Cognitive maps
Tolman - Reinforcement
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Latent learning
Reinforcement influences motivation and
hence performance, but learning itself is
an independent process.
Tolman’s - Legacy
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Behaviorism could be more…
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Set up the cognitive movement…
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Springboard for work in:
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Motivation
Clinical Psychology
Neuropsychology
B.F. Skinner
Skinner Box
Skinner Box
Skinner’s Basic Law of Operant
Conditioning
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A response that is followed by a reinforcer
is strengthened and is therefore more
likely to occur again.
A reinforcer is a stimulus or event that
increases the frequency of a response it
follows.
Operant Conditioniing
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1) The reinforcer must follow the
response.
2) The reinforcer must follow immediately.
3) The reinforcer must be contingent on
the response.
What Behaviors Can Be
Reinforced?
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Academic
Social
Psychomotor
Aggression
Criminal Activity
Basic Concepts in OC
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Shaping (Successive approximations)
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Shaping is a means of teaching a behavior
when the free operant level for that behavior
is very low (or when the desired terminal
behavior is different in form from any
responses that the organism exhibits).
The Nature of Reinforcers
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Primary Reinforcer:
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One that satisfies a built-in (perhaps
biological) need or desire.
Examples:
Food
 Water
 Oxygen
 Warmth
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The Nature of Reinforcers
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Secondary (Conditioned) Reinforcers:
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A previously neutral stimulus that has become
reinforcing to an organism through repeated
association with another reinforcer.
Examples:
Praise
 Good grades
 $$$
 Feelings of success
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What Kinds of Consequences Do
We Find Reinforcing?
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Activity reinforcers
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An opportunity to engage in a favorite
activity.
Premack Principle:
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A normally high-frequency response, when it
follows a normally low-frequency response, will
increase the frequency of the low-frequency
response.
What Kinds of Consequences Do
We Find Reinforcing?
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Material reinforcers
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Actual objects like food or toys
Social reinforcers
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Gesture or sign from one person to another
that communicates positive regard like praise
or a smile.
What Kinds of Consequences Do
We Find Reinforcing?
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Positive feedback:
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Provides information as to which responses
are desirable (and which are not).
Examples: material and social reinforcers
What Kinds of Consequences Do
We Find Reinforcing?
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Intrinsic reinforcers
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When an individual engages in a response not
because of any external reinforcers but
because of the internal good feelings (the
intrinsic reinforcers) that such a response
brings.
Examples: feelings of success, feeling
relieved, feeling proud
Schedules of Reinforcement
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Ratio Schedules:
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A schedule in which reinforcement occurs
after a certain number of responses have
been emitted (fixed or variable)
Interval Schedules:
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A schedule in which reinforcement is
contingent on the first response emitted after
a certain time interval has elapsed (fixed or
variable.
Ratio Schedules
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Fixed Ratio (FR):
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Reinforcer is presented after a certain
constant number of responses have occurred.
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Example - 1:3 or 1:10
Produces a high and consistent response rate
Ratio Schedules
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Variable Ratio (VR):
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Reinforcement is presented after a particular,
yet changing, number of responses have been
emitted.
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Example – In a 1:5 VR you may first be reinforced
after four responses, then after seven more, then
after three, etc.
Interval Schedules
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Fixed Interval (FI):
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Reinforcement is contingent on the first
response emitted after a certain fixed time
interval has elapsed.
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Example: The organism may be reinforced for the
first response emitted after five minutes have
elapsed.
Interval Schedules
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Variable Interval (VI):
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Reinforcement is contingent on the first
response emitted after a certain time interval
has elapsed, but the length of that interval
keeps changing from one occasion to the
next.
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Example – The organism may be reinforced for the
first response after five minutes, then the first
response after eight minutes, then the first
response after two minutes, etc.
Operant vs. Classical Conditioning
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Operant Conditioning
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Classical Conditioning
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Better explains
voluntary activity.
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Better explains
involuntary activity.
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Consequences are
contingent on behavior.
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CS not contingent on
behavior.
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Stimuli follow behavior:
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Rat runs maze, receives
reward
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Stimuli precede behavior:
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Bell (CS) precedes salivation
Observational Learning
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Modeling (Albert Bandura)
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People learn by observing the behavior
of others
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Learning occurs without reinforcement
Bandura study on Aggressive Behavior
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Children watch film of adults hitting
& kicking a doll
These children were more aggressive
with the doll than children who didn’t
see the film
TV violence & Aggressive Behavior
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Correlational studies: Children who watch a lot
of violent TV behave more aggressively
Best studies: TV watching controlled, realworld behavior observed.
Finding: TV violence seems to cause increase
in aggressive behavior (mainly in children who
were already aggressive)
Modeling Prosocial Behavior
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Bandura study: Preschool children
overcoming fear of dogs
Bandura study: Shy children learn to
interact with others