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PSY 402
Theories of Learning
Chapter 7 – Behavior & Its Consequences
Instrumental & Operant Learning
Two Early Approaches
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Reinforcement Theory
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Thorndike’s “Law of Effect” for cats in the puzzle
box.
Skinner boxes – rats pressing bars
Contiguity Theory
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Guthrie – association is enough
Estes – Stimulus Sampling Theory
Problems with Contiguity Theory
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Guthrie proposed that no reinforcement was
needed – just contiguity (closeness) in time
and place.
If learning is immediate and one-trial, why are
learning curves gradual?
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Only a few stimulus elements are associated on
each trial, but more build up with each trial.
His view was wrong but influential (Estes).
Guthrie & Reinforcement
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The reinforcer is salient, so it changes the
stimulus (environmental situation).
Reward keeps competing responses from
being associated with the initial stimulus.
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Competing responses are instead associated with
the presence of the reward.
Fixity of cat flank-rubbing supported Guthrie
but was later shown to be related to the
presence of the experimenter instead.
Tolman’s Operational Behaviorism
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His theories relied on “intervening variables”
not mechanistic S-R associations.
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Behavior is motivated by goals.
Behavior is flexible, a means to an end.
Rats in mazes form cognitive maps of their
environment.
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Animals learn about stimuli, not just behavior.
Evidence of Cognitive Maps
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Changing the maze layout resulted in running
toward the same “goal.”
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A light could have been used as a cue in both
situations.
Using a “plus maze,” some rats were trained
to always turn a certain direction, while others
were trained to reach a consistent place.
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The consistent place was easier to learn.
Latent Learning
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Rats were given experience in a complex
maze, without reward.
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Later they were rewarded for finding the goal
box.
Performance (number of errors) improved greatly
with reward, even among previously unrewarded
rats.
Reward motivates performance, not learning.
Skinner’s Contribution
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Skinner was uninterested in theory – he
wanted to see how learning works in practice.
Operant chambers permit behaviors to be
repeated as often as desired – more voluntary.
Superstitious behavior – animals were
rewarded at intervals without regard to their
behaviors.
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Animals related whatever they were doing to the
reward, and wound up doing odd things.
Stimulus Control
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Skinner discovered that stimuli (cues) provide
information about the opportunity for
reinforcement (reward).
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The stimulus sets the occasion for the behavior.
Fading – gradually transferring stimulus
control from a simple stimulus to a more
complex one.
Operant behavior is controlled by both stimuli
and reinforcers.
Discriminative Stimuli
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Discriminative stimuli act as “occasion
setters” (see Chap 5) in classical conditioning.
The stimulus that signals the opportunity for
responding and gaining a reward is SD.
The stimulus that signals the absence of
opportunity is SD.
Types of Reinforcers
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Primary reinforcer – stimuli or events that
reinforce because of their intrinsic properties:
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Food, water, sex
Secondary reinforcer – stimuli or events that
reinforce because of their association with a
primary reinforcer:
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Money, praise, grades, sounds (clicks)
Called conditioned reinforcers.
Behavior Chains
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Secondary (conditioned) reinforcers reward
intermediate steps in a chain of behavior
leading to a primary reinforcer.
Secondary reinforcers can also be
discriminative stimuli that set the occasion for
more responding.
Classical conditioning is a glue that enables
chains of behavior leading to a goal.