Title: Learning
1Learning
- Foundation of Behaviorism
- Promoted by John B. Watson
- Psychology
- should be an objective science
- study behavior not mental processes
2Definition 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
3Learning
- 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)
4Habituation
- 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).
5Association
Event 1
Event 2
- Learning to associate two events
Sea snail associates splash with a tail shock
Seal learns to expect a snack for its show-off
behavior
6Associative Learning
- Classical Conditioning associating two stimuli,
generally one acts as a signal for the other - Operant Conditioning associating a behavior and
its consequences
7Classical Conditioning
- We learn to associate two stimuli one signals
the other
8Operant Conditioning
- We learn to associate a response with its
consequence
9Classical or Pavlovian Conditioning
- Ivan Pavlov
- 1849-1936
- Russian neurophysiologist
- studied digestive secretions
- invented Classical Conditioning
10Classical Conditioning
- Pavlovs device for recording salivation
11Pavlovs Experiment
12Classical Conditioning
13Classical 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)
14Effect of unreinforced trials (tone without food
following it)
15Classical 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
16What makes a good signal
17Classical 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
18GeneralizationLittle Albert
19Cognitive 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 weeks 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 -
20Classical 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
21- Reliable signal? Informative and contingent
22Temporal 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
23Informativeness 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
24Blocking
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
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26Classical Conditioning
- Goes awry
- Normally neutral stimulus becomes signal of
negative CR
27Nausea Conditioning among Cancer Patients
28Classical 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)
29Siegel (1977, 1983)
- Demonstrated that classical conditioning
principles might be in effect during
drug-injecting episodes - Possible reason for overdoses
30Siegel (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) -
31Siegel (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
32Atkinson, Krank, and McCully (1982)
- Lab rats preconditioned to tolerate large doses
of heroin -
- Trial 1.Room 1.SalineRats okay
- Trial 1.Room 1.Drug.Rats get high
- Trials 2-19 are identical to Trial 1
-
- Trial 20.Room 2.SalineRats okay
- Trial 20 Room 2.Drug..Rats die
33Atkinson, Krank, and McCully (1982)
- Results
- gt50 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) -
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35Operant Conditioning
- Law of Effect (Thorndike)
- Rewarded behavior is repeated
- Operant Conditioning
- behavior strengthened if followed by
reinforcement - behavior weakened if followed by punishment
36Trial-and-error learning
37A cats Behavioral Repertoire (here, for escaping
an enclosed space)
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40Operant Conditioning
- Operant Behavior
- voluntary behaviors
- operates acts on environment
- Behavior ? Consequences
- Reinforcer
- any event that follows behavior AND
strengthens it
41Operant Conditioning
- B.F. Skinner (1904-1990)
- Built on Thorndikes Law of Effect
- Discovered schedules of reinforcement
42Operant Conditioning
- Operant Chamber (Skinner Box)
- chamber with a bar that an animal can press to
obtain a food reinforcer - Frequency of responses are recorded
43Principles 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
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45Schedules 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
46Schedules of Reinforcement
47Schedules 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
48Schedules of Reinforcement
- Variable Ratio (VR)
- behavior is reinforced after an unpredictable
number of times - like gambling, fishing
- very hard to extinguish because of
unpredictability
49Schedules 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
50Schedules of Reinforcement
- Variable Interval (VI)
- behavior is reinforced at unpredictable time
intervals - produces slow, steady responding
- like pop quiz!
51Reinforcement 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
52Discrimination Demo
- 1 for getting right answer, owe 1 for wrong
- Mother Father Friend (triangle)
- - Son Sister Uncle
53Shaping
- Can leave lab once rat touches lever three times
in 10 seconds
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55Shaping
- Successive approximations to goal behavior
56Punishment
- An aversive event that decreases the behavior
that it follows
57Reinforcement Punishment
- Positive reinforcement
- Negative reinforcement
- Positive punishment
- Negative punishment
58Operant Conditioning
Positive negative reinforcement Positive
negative punishment
59Problems 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
60Operant vs Classical Conditioning
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62Behaviorism 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 Chomskys critique
- marked the end of behaviorism as the dominant
paradigm of psychology
63Latent 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
64Behaviorism 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 Chomskys critique
- marked the end of behaviorism as the dominant
paradigm of psychology
65Observational Learning
- Bobo Doll study (Bandura)
66Behaviorism 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 Chomskys critique
- marked the end of behaviorism as the dominant
paradigm of psychology
67Language 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
68Is brain-behavior behavior?
- If so, it can be conditioned just like other
behaviors - Two current fields Neurotherapy and
Brain-Computer interfaces (BCI)
69Electrical 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
70INTRA-CRANIAL SELF-STIMULATION
- 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 gamma-aminobutyric acid (GABA) system, an
important component of the final common pathway"
of reward, implicated in addiction, mood, and
learning.
71Biofeedback
- Neal E Miller trained autonomic functions
- Rats control heartrate to get water
- Dogs salivate to get food
72/- 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
73Two forms of Biofeedback PNS CNS (peripheral
and central)
- Peripheral Body (skin) temperature, GSR (skin
conductance), muscle (EMG), heart rate
variability, breathing, pulse
74CNS Central Nervous System biofeedback
When you become aware of your own brain
activityyou can change it