Transcript CH 4: Learning - psychfiles.net

Basic Processes of Learning
Chapter 4
Principles of Learning
 The environment is always fluctuating
 LEARNING: the process or set of processes through which
sensory experience at one time can affect an individual’s
behavior at a future time
 Experience: any effects in the environment that are
mediated by the individual’s sensory systems
Classical Conditioning: Part I
 Classical conditioning is a learning process that creates
new reflexes
 REFLEX: a simple, relatively automatic, stimulus-response
sequence mediated by the nervous system
Tap on
the
knee
•Nerves
•Spinal
Cord
Leg
jerks
forward
 HABITUATION: the decline in the magnitude or likelihood of
a reflexive response that occurs when the stimulus is
repeated several times in succession
Pavlov’s Discovery
 Ivan Pavlov (1849-1936)
 Studied the reflexes
involved in digestion
 Could some other stimulus
be triggering the salivating
response in dogs?
Classical Conditioning
Extinction and Recovery from
Extinction
• The gradual disappearance of a conditioned
reflex that results when the CS occurs repeatedly
without the UCS
• The return-due to the passage of time with no
further testing or training-of a CR that had
previously undergone extinction
Extinction and Spontaneous
Recovery
Generalization and Discrimination
• The phenomenon by which a stimulus that resembles
a CS will elicit the CR even though is has never been
paired with the UCS
• Procedure by which generalization between two
stimuli is diminished or abolished by reinforcing the
response to one stimulus and extinguishing the
response to the other
Classical Conditioning and
Behaviorism
 BEHAVIORISM: (early 20th
century) school of
psychological thought that
holds the proper subject of
study is observable
behavior, not the mind
 Behavior should be studied
through an environmental
context, not an internal,
individualistic context
 John B. Watson
Poor Little Albert…
Stimulus-stimulus associatons
 Pavlov’s Stimulus-Stimulus Theory
 Watson’s Stimulus-Response Theory
Learned Expectancy

Rescorla (1998): Classical conditioning is not a stupid process by which the
organism willy-nilly forms associations between any two stimuli that happen to cooccur. Rather, the organism is best seen as an information seeker using logical
and perceptual relations among events, along with its own preconceptions, to
form a sophisticated representation of its world.

Translation: The dog expects the food.
• Classical conditioning does not occur if the CS and UCS occur simultaneously or the CS
follows the UCS
• As the number of pairings increases, so does the strength of the association. Internal
probability calculation?
• The Blocking Effect – new stimulus presented with CS does not become a new CS.
Conditioned Fear, Hunger and Sexual
Arousal
Conditioned Drug Reactions

Drugs have two effects: the main
effect and a compensatory effect
that stabilizes the body

DRUG TOLERANCE: the
phenomenon by which a drug
produces successively smaller
physiological and behavioral
effects, at any given dose, if it is
taken repeatedly

Overdosing
A Clockwork Orange
Operant Conditioning I
 OPERANT CONDITIONING: a training or learning process
by which the consequence of a behavior response
affects the likelihood that the individual will produce the
response again
 Edward Thorndike
(1898)
 Cats in the puzzle box
 LAW OF EFFECT: Responses that produce a satisfying effect in a
particular situation become more likely to occur again in that situation
Burrhus Frederic (“BF”) Skinner
 Researched and
popularized the theory of
operant conditioning
 Skinner box
 REINFORCER: any stimulus
change that occurs after
a response and tends to
increase the likelihood
that the response will be
repeated
Principles of Reinforcement
How do you establish the first response?
 SHAPING: procedure in which
successively closer
approximations to the desired
response are reinforced until
the response finally occurs
 EXTINCTION: the decline in
response rate that results
when an operant response is
no longer followed by a
reinforcer
Schedules of Partial Reinforcement (vs. continuous
reinforcement)
•A reinforcer occurs after every 9th response, where n is some whole number
greater than 1
•The number of responses required before reinforcement varies unpredictably
around some average
•A fixed period of time elapses between one reinforced response and the next
•The period of time that must elapse before a response will be reinforced varies
unpredictably around some average
Reinforcement and Punishment
Positive
(Introducing
something)
Negative
(Removing
something)
Manipulation
Goal
INCREASES TARGET
BEHAVIOR
DECREASES TARGET
BEHAVIOR
Positive Reinforcement
(Lever Press  Food
pellet)
Positive Punishment
(Lever Press  Shock)
+ Add something good
+ Add something bad
Negative Reinforcement
(Lever Press  Shock off)
Negative Punishment
(Lever Press  removes
food)
- Take away something bad
- Take away something good
The Big Bang Theory
https://www.youtube.com/watch?v=JA96Fba-WHk
Operant Conditioning II
Through discrimination training, an
animal can be conditioned to make an
operant response to a stimulus more
specific than the entire inside of a
Skinner Box.
 Discriminative stimulus
GENERALIZATION
The Overjustification Effect
 OVERJUSTIFICATION EFFECT: the phenomenon in
which a person performs a task for no reward
becomes less likely to perform that task for no reward
after a period of time during which he or she has
been rewarded for performing it
 Cognitive consequences of rewards
Facilitating Learning: PLAY
 Exercise or activity for
amusement or recreation; has
no useful purpose
 Allows the animal to practice
their instincts or species-specific
behavior
 Groos’ Theory of Play
1. the young play more than
adults
2. Species that have the most to
learn play the most
 Play in humans: a form of
imitation
Facilitating Learning: EXPLORATION
 EXPLORATION: the
investigation of unknown
regions
 A more primitive form of
learning
 A balance of curiosity and
fear
Exploration: Information
Acquisition
 Tolman and Honzik (1930):
Rewards affect what
animals do more than
what they learn
 LATENT LEARNING:
learning that is not
demonstrated in the
subject’s behavior at the
time that the learning
occurs but can be
inferred from its effect on
the subject’s behavior at
some later time
Facilitating Learning: OBSERVATION
 OBSERVATIONAL LEARNING:
learning by watching others
 Stimulus enhancement:
increase in the salience or
attractiveness of the object
that the observed individual
is acting upon
 Goal enhancement: an
increased drive to obtain
rewards similar to what the
observed individual is
receiving
Food-Aversion Learning
 What is safe to eat?
 Most animals learn to avoid foods that have made them ill
 Food aversion differs from classical conditioning because:
 A significant time delay
 CS must be a taste or smell
Food Preference Learning
 Animals must also learn to choose foods that satisfy a
nutritional requirement, can associate certain foods with
improvement in health
 Humans have a preference for high-calorie foods:
(evolutionary advantageous)