Download Introduction to Psychology

Learning
 Foundation
of Behaviorism
Promoted by John B. Watson
Psychology…
should be an objective science
study behavior not mental processes
Definition of Learning
Learning is an adaptive1 permanent
change2 in behavior or behavior potential3
that is produced as a result of prior
experience4
 1 occasionally maladaptive such as depressed mental set,
obsessions
 2 not due to fatigue, injury
 3 includes tendencies to respond that might not have been tested
 4 excludes maturation, disease, instinct
Learning
Can there be learning that does not result in a
change in behavior?
Types of Learning
Habituation (simple, single stimulus)
Associative Learning (simple, passive,
external)
Cognitive Learning (complex, strategic,
internal)
Habituation
 Simplest form of learning
 Response to repeated stimulus declines across repetitions.
 Not due to fatigue because response will reoccur if
stimulus is changed.
 non-associative learning as it involves only one stimulus.
 Associative learning involves two stimuli
(one is associated with the other).
Association
Event 1
Event 2
Sea snail associates splash with a tail shock
Seal learns to expect a snack for its show-off behavior
Learning to
associate two
events
Associative Learning
Classical Conditioning – associating
two stimuli, generally one acts as a signal
for the other
Operant Conditioning – associating a
behavior and its consequences
Classical Conditioning
Two related events:
Stimulus 1
Lightning
Stimulus 2
Thunder
Result after repetition
Stimulus
We see
lightning
Response
We wince
anticipating
thunder
We learn to
associate two
stimuli – one
signals the
other
Operant Conditioning
We learn to
associate a
response with
its consequence
Response: Pushing
vending machine button
Consequence:Receiving
a candy bar
Classical or Pavlovian
Conditioning
Ivan Pavlov
1849-1936
Russian
neurophysiologist
studied digestive
secretions
invented Classical
Conditioning
Classical Conditioning
Pavlov’s device for recording
salivation
Pavlov’s Experiment
Before Conditioning
UCS (food
in mouth)
UCR
(salivation)
During Conditioning
Neutral
stimulus
(tone)
No
salivation
After Conditioning
UCS (food
in mouth)
Neutral
stimulus
(tone)
UCR
(salivation)
CS
(tone)
CR (salivation)
Classical Conditioning
Strong
Acquisition
(CS+UCS)
Extinction
(CS alone)
Spontaneous
recovery of
CR
Strength
of CR
Extinction
(CS alone)
Weak
Pause
Time
Classical Conditioning
 Unconditioned Stimulus (UCS)
stimulus automatically
triggers a response
food in mouth
 Unconditioned Response (UCR)
unlearned automatic
response to unconditioned
stimulus
you salivate when food
is in your mouth
“physiological (hard-wired) association”
 Conditioned Stimulus (CS)
neutral stimulus becomes
associated with UCS
triggers (conditioned)
response
 Conditioned Response (CR)
Nearly the automatic
response
But it is learned, slightly
weaker (a bit less
salivation in our example)
Effect of unreinforced trials
(tone without food following it)
Classical Conditioning
Acquisition
the initial stage of learning, during which a
response is established and gradually
strengthened
Extinction
diminishing a conditioned response
occurs when an unconditioned stimulus
does not follow a conditioned stimulus
What makes a good signal
Classical Conditioning
 Spontaneous recovery
reappearance, after a rest period, of an extinguished
conditioned response
 Generalization
tendency for stimuli similar to the conditioned stimulus to
evoke similar responses
 Discrimination
the ability to distinguish between a conditioned stimulus and
other similar stimuli that do not signal an unconditioned
stimulus
Generalization:
Little Albert
Cognitive Development
“Never hug and kiss them, never let them sit on your lap. If you must,
kiss them once on the forehead when they say good night. Shake
hands with them in the morning. Give them a pat on the head if they
have made an extraordinarily good job of a difficult task. Try it out. In
a week’s time you will find how easy it is to be perfectly objective with
your child and at the same time kindly. You will be utterly ashamed at
the mawkish, sentimental way you have been handling it.”
—John Watson
“Psychological Care
of Infant and Child”
Classical Conditioning
Temporal Contiguity was thought to be
sufficient – the CS simply needs to occur
immediately prior to the UCS for
conditioning to take place
Equipotentiality: any two stimuli could
be associated through conditioning
Reliable signal? Informative and contingent
Temporal Contiguity is Not
Enough
Contingency: The CS must reliably
predict the occurrence of the UCS
(Rescorla, 1966)
Informativeness: The CS must provide
new information for predicting the
occurrence of the UCS
Informativeness: Blocking
If an organism has already learned that
one CS predicts the UCS, that will block
the conditioning of a new CS if the new
CS does not provide any additional
information
Example: Fear conditioning of a tone
blocks conditioning of a light
Blocking
Training 1 Training 2
Test
-none-
Tone & Light,
shock
(CR = fear)
Light 
Fear
Tone, shock
(CR = fear)
Tone & Light,
shock
(CR = fear)
Light 
No Fear
Classical Conditioning
Goes awry
Normally neutral stimulus becomes
signal of negative CR
Nausea Conditioning
among Cancer Patients
UCS
(drug)
UCR
(nausea)
CS
(waiting
room)
UCS
(drug)
UCR
(nausea)
CS
(waiting
room)
CR
(nausea)
Classical Conditioning
Drug Tolerance Example
Drug Tolerance
Drugs have less of an effect when taken
repeatedly (less of a high)
Drug users crave more of the drug despite its
lessening effects
Certain drugs trigger our body to call upon
its defenses against the effects of the drug
(parasympathetic or shutdown system)
Siegel (1977, 1983)
Demonstrated that classical conditioning
principles might be in effect during druginjecting episodes…
Possible reason for overdoses
Siegel (1977, 1983)
 UCS ---------------------------------------------- UCR
(drug)
(anti-drug defenses)
 CS ----------------------------------------------- NO RESPONSE
(injection ritual)
(no defenses)
 CS + UCS -------------------------------------- UCR
(injection ritual) + (drug)
(anti-drug defenses)
* Repeated several times
 CS ----------------------------------------------- CR
(injection ritual)
(anti-drug defenses)
Siegel (1977, 1983)
 Familiar setting-------------------- anti-drug defenses
(usual time, place, etc)
(body reacts)
 New setting ---------------------------- no defenses
(place, time are different)
(body doesn't react)
Same dosage becomes an overdose – they
get too high as their bodies have been
fooled by the new procedure, no signals to
start dampening down of response
Atkinson, Krank, and McCully (1982)
Lab rats preconditioned to tolerate large doses of
heroin…
Trial 1……….Room 1…………….Saline………Rats okay
Trial 1……….Room 1…………….Drug……….Rats get high
Trials 2-19 are identical to Trial 1…
Trial 20…….Room 2…………….Saline………Rats okay
Trial 20…… Room 2…………….Drug………..Rats die
Atkinson, Krank, and McCully
(1982)
Results:
>50% increase in death rate in new room
Rats show "room-specific" tolerance
May explain overdoses in humans
Practical implications as far as detoxification
is concerned (returning clean addict to
street, friends)
Operant Conditioning
Law of Effect (Thorndike)
Rewarded behavior is repeated
Operant Conditioning
behavior strengthened if followed by reinforcement
behavior weakened if followed by punishment
Trial-and-error learning
A cat’s Behavioral Repertoire (here,
for escaping an enclosed space)
Operant Conditioning
Operant Behavior
 voluntary behaviors
 operates [acts] on environment
 Behavior  Consequences
Reinforcer
 any event that follows behavior AND
strengthens it
Operant Conditioning
B.F. Skinner (19041990)
Built on Thorndike’s
Law of Effect
Discovered
schedules of
reinforcement
Operant Conditioning
Operant Chamber
(“Skinner Box”)
chamber with a bar
that an animal can
press to obtain a
food reinforcer
Frequency of
responses are
recorded
Principles of
Reinforcement
Primary Reinforcer
innate reinforcer, satisfies biological need
e.g., food, water, warmth
Secondary Reinforcer
conditioned reinforcer, gains its reinforcing
power through association with primary
reinforcer
e.g., money
Schedules of
Reinforcement
Continuous Reinforcement
reinforcing the desired response each time it
occurs
learning occurs rapidly
extinction occurs rapidly
Partial Reinforcement
reinforcing a response only part of the time
learning occurs slowly
resistance to extinction
Schedules of
Reinforcement
Number of
responses
1000
Fixed Ratio
Variable Ratio
Fixed Interval
750
Rapid responding
near time for
reinforcement
500
Variable Interval
250
Steady responding
0
10
20
30
40
50
Time (minutes)
60
70
80
Schedules of
Reinforcement
Fixed Ratio (FR)
behavior is reinforced only after the behavior
occurs a specified number of times
the faster you respond, the more rewards
you get!
different ratios
very high rate of responding
like piecework pay
Schedules of
Reinforcement
Variable Ratio (VR)
behavior is reinforced after an
unpredictable number of times
like gambling, fishing
very hard to extinguish because of
unpredictability
Schedules of
Reinforcement
Fixed Interval (FI)
behavior is reinforced only after a
specified time has elapsed
frequency of behavior increases when
the time for reward draws near
Schedules of
Reinforcement
Variable Interval (VI)
behavior is reinforced at
unpredictable time intervals
produces slow, steady responding
like pop quiz!
Reinforcement Schedule
examples
Buying a lottery ticket and winning vr
Watching & seeing a shooting star vi
Receiving allowance Saturday for having
clean room fi
Hotel maid gets 15-min break after cleaning
four rooms fr
Discrimination Demo
$1 for getting right answer, owe $1 for
wrong
 + Mother
 - Son
Father
Sister
Friend (triangle)
Uncle
Shaping
Can leave lab once rat touches lever three
times in 10 seconds
Shaping
Successive approximations to goal
behavior
Punishment
An aversive event that decreases
the behavior that it follows
Reinforcement &
Punishment
Positive reinforcement
Negative reinforcement
Positive punishment
Negative punishment
Operant Conditioning
Appetitive
Presented Positive
reinforcement
Positive event follows
response e.g. reward
Removed Punishment
Positive state
removed after
response e.g. time-out
or omission training
Aversive
Punishment
Discomfort follows
response e.g.
punishment
Negative
reinforcement
Discomfort removed
after response e.g.
escape or avoidance
learning
Positive & negative reinforcement
Positive & negative punishment
Problems with Punishment
Punished behavior is not forgotten, it's merely
suppressed
behavior returns when punishment removed
Causes increased aggression
Creates fear
That may generalize to undesirable behaviors, e.g.,
fear of school
Does not necessarily guide toward desired
behavior
reinforcement tells you what to do
punishment tells you what not to do
Punishment teaches you mostly how to avoid it
Operant vs Classical
Conditioning
Comparison of Classical and Operant Conditioning
Classical Conditioning
Operant Conditioning
The response
Involuntary, automatic
“Voluntary,” operates on environment
Acquisition
Associate events; CS signals UCS
Associate response with a consequence
(reinforcer or punisher).
Extinction
CR decreases when CS is repeatedly
presented alone.
Responding decreases when reinforcement
stops.
Cognitive
processes
Subjects develop expectation that
CS signals the arrival of UCS
Subjects develop expectation that a
response will be reinforced or punished;
they also exhibit latent learning, without
reinforcement.
Biological
Natural predispositions constrain
predispositions which stimuli-responses can easily
be associated.
Organisms best learn behavior similar to
their natural behaviors; unnatural behaviors instinctively drift back toward
natural ones.
Behaviorism cannot explain:
 Latent Learning – learning without reinforcement
(Tolman & Honzig, 1930)
 Observational Learning – learning without behaving
or being reinforced directly (Bandura, 1977)
 Overjustification – when rewards decrease the
frequency of behavior
 Language Acquisition – Chomsky’s critique
marked the end of behaviorism as the dominant paradigm of
psychology
Latent Learning: learning that occurs but is not apparent
until there is a reinforcer to demonstrate it
Group 1: no food reward Group 2: always food reward Group 3: food after 10 days
Behaviorism cannot explain:
 Latent Learning – learning without reinforcement
(Tolman & Honzig, 1930)
 Observational Learning – learning without behaving
or being reinforced directly (Bandura, 1977)
 Overjustification – when rewards decrease the
frequency of behavior
 Language Acquisition – Chomsky’s critique
marked the end of behaviorism as the dominant paradigm of
psychology
Observational Learning
Bobo Doll study (Bandura)
Behaviorism cannot explain:
 Latent Learning – learning without reinforcement
(Tolman & Honzig, 1930)
 Observational Learning – learning without behaving
or being reinforced directly (Bandura, 1977)
 Overjustification – when rewards decrease the
frequency of behavior
 Language Acquisition – Chomsky’s critique
marked the end of behaviorism as the dominant paradigm of
psychology
Language acquisition
 Chomsky: Association is insufficient to explain language learning.
We acquire RULES of language, not instances
 Evidence: Over-regularization (“goed”)
 Conclusion: Mere associations between words cannot explain
language
 Behaviorism lacks
 Symbolic Representation – we have (internal) representations for
things in the world
 Structure – we learn sets of rules for combining symbols (e. g.,
grammar), not mere associations between pairs of symbols
 Lead to Cognitive paradigm in psychology
Is brain-behavior behavior?
 If so, it can be
conditioned just
like other
behaviors
 Two current
fields:
Neurotherapy and
Brain-Computer
interfaces (BCI)
Electrical stimulation of brains
(ESB)
 Electrical stimulation of brains of rats James Olds in 1950s;
Jacobsen and Torkildsen replicated work
in humans;
some epileptics stimulated themselves
into convulsions

INTRA-CRANIAL SELFSTIMULATION
 Rodent wireheads
0.0005 amperes for less than a second whenever rat pushed
lever
Rates of up to 10,000 bar-presses an hour recorded
Medial forebrain bundle passing through lateral hypothalamus
and ventral tegmentum
An animal will self-stimulate for more than 24 hrs continuously
without rest, and will cross electrified grid to gain access to lever
Other brain centers are aversive, such as periaqueductal grey
matter (PAG)
Ventral tegmental area (VTA) neurons manufacture dopamine
and they are under continuous inhibition by gammaaminobutyric acid (GABA) system, an important component of
the ”final common pathway" of reward, implicated in addiction,
mood, and learning.
Biofeedback
Neal E Miller trained
autonomic functions
Rats control heartrate
to get water
Dogs salivate to get
food
+/- together leads to organism
shutdown (internal inhibition)
 Pavlov conditioning experiments
 Tone for food, buzzer for shock –
 Moved them closer together in time
 confounded dog fell asleep
Termed “internal inhibition”
Animal can close down own systems to
avoid stress
Two forms of Biofeedback: PNS & CNS
(peripheral and central)
Peripheral: Body
(skin) temperature,
GSR (skin
conductance), muscle
(EMG), heart rate
variability, breathing,
pulse
CNS: Central Nervous System biofeedback
When you become aware of your own brain activity–you can change it