Transcript Powerpoint

PSY402
Theories of Learning
Chapter 12 (pg 303-327)
Biological Influences on Learning
Limits to Learning
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How general are the laws of
learning?
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Skinner’s rules work in both lab and
real-world settings, across species.
Learning doesn’t explain all aspects
of behavior.
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Organization of behavior already exists
within an organism.
Learning modifies that organization.
Behavior Systems Approach
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Timberlake – learning changes the
integration, tuning, instigation or
linkages within a behavior system.
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Different cues are salient to different
behavior modes.
Variations in learning occur across
species because their behavior systems
are different.
Variations in behavior are the result
of predispositions and constraints.
Animal Misbehavior
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Breland & Breland – trained 38
species of animals for Busch
Gardens.
Elicitation of foraging and foodhandling instincts interferes with
performance of operant routines.
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Instinctive drift
Pig and piggy bank
Raccoons and food-washing
Explaining Misbehavior
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Does misbehavior result from
operant food reinforcement or
classical conditioning?
Timberlake’s appetitive structure
view – both kinds of learning
contribute to animal misbehavior.
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Pairings with food are necessary but
not sufficient to evoke misbehavior.
Schedule-Induced Behavior
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Superstitious behavior – induced by
FI schedules.
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Animal associates whatever it is doing
at the time with the reinforcement.
Ritualistic, stereotyped behavior during
the interval.
Two kinds of behavior:
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Terminal – reinforcer-oriented
Interim – follows reinforcement.
Effects with Humans
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Superstitious gambling behavior.
Schedule-induced behavior may be
related to alcoholism:
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Excessive drinking, eating, smoking
may occur immediately after
reinforcement.
Weak and inconsistent in humans.
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Develops rapidly in humans, stops
quickly
Flavor-Aversion Learning
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Long-delay learning – does not
depend on contiguity.
Preparedness – certain stimuli are
innately more likely to be
associated with a UCS than others.
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Visual cues more salient to birds
Taste cues more salient to rats
Salience depends on when the animals
seeks its food (nocturnal or not).
Applications
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Cancer chemotherapy (UCS)
causing nausea may be associated
with hospital food (CS).
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Preexposure to food without the toxic
drug or drug without food may help
prevent food aversions.
Coyotes and wolves can be taught
to avoid attacking and eating sheep
using flavor-aversion learning.
Explanations
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Learned-Safety theory – an evolved
mechanism unique to flavoraversion to protect animal.
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Ingestional neophobia – small
quantities consumed at first.
Concurrent-Interference view – long
delay occurs because the animal
doesn’t eat anything else for a while
Imprinting
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Lorenz – social attachment process
where young ducks follow their
mother.
Ducks imprint to:
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Moving objects with lifelike motion
Vocalizing objects, short rhythmic
sounds, not high-pitched
Objects that are the right size
Other Factors in Imprinting
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Harlow – baby primates attach to
soft terry cloth rather than wire.
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Rocking rather than stationary
Warm rather than cold
Ainsworth – attachment to a
responsive mother.
Occurs more easily during sensitive
period of animal’s life.
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6 to 12 months for humans
Other Kinds of Imprinting
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Sexual preferences – occurs early in
development, long before sexual
maturity, not modifiable later.
Food preferences – preferences
established early and permanent.
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People prefer familiar foods
Food aversions develop between 6 & 12
yrs
Nature of Imprinting
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Both instinctive and associative
processes are involved.
Associative-learning view – objects
become familiar before fear system
matures
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Familiar objects reduce fear later, so
become preferred due to relief.
Harlow’s studies contradict this.
Some objects are more imprintable.
Instinctive View of Imprinting
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Organisms contain an innate
schema of the imprinting object
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Evoluntary pressure to learn the right
thing.
Response is hard to change.
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Extinction does not lead to loss of
preference.
Abused primates and children cling to
abusive mothers despite punishment.
Avoidance of Aversive Events
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Species-specific defense reactions
(SSDR) – instinctive responses to
specific dangers.
Rats – running, freezing, fighting.
Cues predicting danger also select
the specific response.
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Escape and avoidance behaviors are
learned more readily when they
incorporate SSDR.