Download Chapter 6: Learning (Classical Conditioning)

LEARNING
Chapter 6 (Bernstein), pages 194-229
What is LEARNING?
LEARNING is the adaptive process through which experience modifies pre-
existing behavior and understanding; relatively permanent change in behavior based
on prior experiences
plays central role in development of most aspects of human behavior
humans and animals learn primarily by:
1. experiencing events
2. observing relationships between those events
3. noting consistencies in the world around them
3 guiding questions of psychological research on learning:
1. Which events and relationships do people learn about?
2. What circumstances determine whether and how people learn?
3. Is learning a slow process requiring lots of practice OR does it involve sudden
flashes of insight?
LEARNING ABOUT STIMULI
HABITUATION and SENSITIZATION
People appear to be genetically tuned to attend to and orient toward certain kinds of events.
These novel stimuli attract attention.
loud sounds
special tastes
bright lights
pain
Learning that involves exposure to a single stimulus is referred to as non-associative learning.
Two simple forms of non-associative learning: habituation and sensitization
Unchanging stimuli decrease our responsiveness, and we adapt to such stimuli
(habituation)
After a response to a stimulus is habituated, dishabituation, or reappearance of the
original response, occurs if the stimulus changes.
Sensitization is an increase in responsiveness to a stimulus. (e.g.,people & animals show
exaggerated responses to unexpected, potentially threatening sights or sounds, especially when
aroused.)
LEARNING ABOUT STIMULI
Richard Solomon’s OPPONENT PROCESS THEORY
New stimulus events, esp. those arousing strong emotions, disrupt a person’s equilibrium.
This disruption triggers an opposite (opponent) response (process) that eventually restores
equilibrium.
If the event occurs repeatedly, the opponent process becomes stronger and eventually
suppresses the initial reaction to the stimulus, creating habituation.
e.g., development of drug tolerance and addiction
e.g., engagement in high risk/arousal activities such as skydiving
e.g., accidental drug overdoses
NOTE: Opponent process explanations based on habituation and sensitization cannot explain
many of the behaviors and mental processes that are the focus of psychology.
Learned associations between certain environmental stimuli and certain opponent responses
affect our thoughts and behaviors as well.
CLASSICAL CONDITIONING is one type of associative learning that builds associations
between various stimuli as well as between stimuli and responses
CLASSICAL CONDITIONING:
Learning Signals and Associations
Pavlov’s Discovery
Pavlov's "Classic" Study
Russian physiologist Ivan Pavlov’s classic experiment
taught a dog to salivate to a musical tone.
First, Pavlov confirmed a dog salivates when meat is
put on its tongue (reflex) but not when a tone sounds
(neutral stimulus).
reflex a swift, unlearned automatic response to a
stimulus
neutral stimulus a stimulus that initially does not
trigger the reflex being studied
second, he repeatedly paired the tone and the meat;
each time he sounded the bell, he put a bit of meat
powder in the dog’s mouth (the tone predicted that
meat powder was coming).
eventually, the dog salivated to the tone alone...even if
no meat powder was given.
Pavlov’s experiment showed a form of associative
learning call CLASSICAL CONDITIONING.
Classical Conditioning Scene
from “The Office”
CLASSICAL CONDITIONING:
Learning Signals and Associations
CLASSICAL
CONDITIONING
a form of associative learning in which a
neutral stimulus is repeatedly paired with a
stimulus that already triggers a reflexive
response until the neutral stimulus alone
triggers a similar response
unconditioned stimulus (UCS) the
stimulus that already elicits a response
without learning
unconditioned response (UCR) the
automatic response to the UCS
conditioned stimulus (CS) the neutral
stimulus that is repeatedly paired with the
unconditioned stimulus
conditioned response (CR) the reaction
resulting from the pairing of the UCS and
the CS in which the CS alone elicits a
learned or “conditioned” response
CLASSICAL CONDITIONING:
Learning Signals and Associations
CLASSICAL CONDITIONING:
Learning Signals and Associations
CONDITIONED RESPONSES OVER TIME
EXTINCTION the CS occurs without UCS and the association gradually
weakens until the CR disappears; the association is not erased, just suppressed
RECONDITIONING the relearning of the CR after extinction; requires
fewer pairings of the CS with the UCS than the original learning (because
extinction does not erase the association)
SPONTANEOUS RECOVERY the sudden reappearance of the CR after
extinction but without further CS-UCS pairings
In general, the longer the time between extinction and the representation of the CS, the stronger the recovered conditioned response
was in the first place.
e.g., when a person hears a song or smells a scent associated with a long-lost
lover and experiences a ripple of emotion (the conditioned response)
CLASSICAL CONDITIONING:
Learning Signals and Associations
STIMULUS GENERALIZATION & DISCRIMINATION
STIMULUS GENERALIZATION when stimuli that resemble the CS and
trigger a CR
The greater the similarity between a new stimulus and the conditioned
stimulus, the stronger the conditioned response
e.g., ____________________
STIMULUS DISCRIMINATION when people and animals learn to
differentiate among similar stimuli
This complements generalization by preventing people (and animals) from
being completely disrupted by overgeneralization.
e.g., ____________________
CLASSICAL CONDITIONING:
Learning Signals and Associations
THE SIGNALING OF SIGNIFICANT EVENTS
Classical conditioning depends on one event reliably predicting or signaling the appearance of
another.
This leads to the development of mental representations of the relationships between important
events in the environment and expectancies about when such events will occur.
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED
1.
TIMING
2.
PREDICTABILITY
3.
SIGNAL STRENGTH
4.
ATTENTION
5.
BIOPREPAREDNESS
6.
SECOND-ORDER CONDITIONING
CLASSICAL CONDITIONING:
Learning Signals and Associations
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED
1.
TIMING The timing of the CS relative to the UCS affects the speed of conditioning.
FORWARD CONDITIONING the CS precedes and thus signals the UCS; works
best when there is an interval between the CS and the UCS (from a fraction of a
second to a few seconds to more than a minute depending on the particular CS, UCS,
and UCR involved)
BACKWARD CONDITIONING the CS follows the UCS; classical conditioning
works most slowly this way (if it even works at all)
2.
PREDICTABILITY not enough for the CS and the USC to just occur together; they must
reliably occur together before classical cond. occurs; cond. is quicker when the CS always
signals the UCS and only the UCS. (e.g., Moxie and Fang’s growling and biting)
3.
SIGNAL STRENGTH CR learned faster when UCS is strong rather than weak; speed with
which a CR is learned also depends on the strength of the CS (e.g., intense shock, louder tone)
4.
ATTENTION The stimulus most closely attended to, most fully perceived at the moment,
dominates the others in later triggering a CR (e.g., getting stung by a wasp at the beach after
putting on sunscreen while sipping lemonade, reading a magazine, and listening to Beyonce’)
CLASSICAL CONDITIONING:
Learning Signals and Associations
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED
5.
BIOPREPAREDNESS It was once believed that any CS had an equal chance of being
associated with any UCS, but this equipotential seems to be incorrect. Some stimuli are
more easily associated with each other, perhaps because organisms are “genetically tuned”
or “biologically prepared” to develop certain conditioned associations. (e.g., taste
aversions...see below)
A) A taste paired with nausea will lead to an aversion to the taste. A light and/or sound
paired with nausea produces no aversion and no learning.
WHY? Something eaten is more likely to naturally cause nausea than an audio-visual stimulus.
B) A taste paired with electric shock will not produce an aversion (learning) to the taste. But
an audio-visual stimulus, such as lights and bells, paired with an electric shock produces
aversion (learning) to pain.
WHY? In real life, organisms should be “tuned” to associate pain from a shock with external stimuli
such as sights or sounds rather than with something eaten.
In sum, animals (including humans) are prone to learn the type of associations that are
most common or relevant to their environment.
CLASSICAL CONDITIONING:
Learning Signals and Associations
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED
6. SECOND-ORDER CONDITIONING This occurs when a CS is paired with a new
stimulus until the new stimulus makes the CS act like a UCS. This creates conditioned
stimuli out of events associated with it.
(e.g., a child who has experienced a painful medical procedure at the doctor’s office)
•
UCS the painful medical procedure
•
CS the doctor’s white coat (the coat signals pain to follow...the UCS)
•
CR conditioned fear of the doctor’s office because of the pain associated with
it
•
If the child later sees a white-coated pharmacist at the drugstore, then...
•
UCS becomes the white coat
•
CS drugstore (the once-neutral store signals the appearance of the white coat)
•
CR second-order conditioned fear of white coat due to pain associated with it
CLASSICAL CONDITIONING:
Learning Signals and Associations
In Review...
CLASSICAL CONDITIONING:
Learning Signals and Associations
APPLICATIONS OF CLASSICAL CONDITIONING
1.
PHOBIAS extreme fears of objects/situations that don’t reasonably warrant such intense fears
SYSTEMATIC DESENSITIZATION the association of a new response (relaxation) with a
feared stimulus; the CR (relaxation) replaces the old CR (fear).
2.
PREDATOR CONTROL
Western ranchers lace mutton with lithium chloride which makes wolves and coyotes ill
after they eat it; this makes sheep an undesirable food.
3.
DETECTING EXPLOSIVES
Researchers are attempting to pair attractive scents with the smell of drugs or chemicals
used in explosives to teach insects (such as wasps) to detect concealed explosives or drugs.
4.
PREDICTING ALZHEIMER’S DISEASE
A puff of air in the eye paired with a flash of light will result in a blink in response to the
light alone through classical conditioning. Elderly people who show an impairment in the
eye blink conditioning are at greater risk for developing Alzheimer’s because the
hippocampus is involved both with the eye blink conditioning and Alzheimer’s disease.