Learning

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Learning

• Foundation of Behaviorism
• Promoted by John B. Watson
• Psychology
• should be an objective science
• study behavior not mental processes

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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

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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)

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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).

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Association
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
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Associative Learning

• Classical Conditioning associating two stimuli,
  generally one acts as a signal for the other
• Operant Conditioning associating a behavior and
  its consequences

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Classical Conditioning

• We learn to associate two stimuli one signals
  the other

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Operant Conditioning

• We learn to associate a response with its
  consequence

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Classical or Pavlovian Conditioning

• Ivan Pavlov
• 1849-1936
• Russian neurophysiologist
• studied digestive secretions
• invented Classical Conditioning

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Classical Conditioning

• Pavlovs device for recording salivation

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Pavlovs Experiment
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Classical Conditioning
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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)

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Effect of unreinforced trials (tone without food
following it)
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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

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What makes a good signal
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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

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GeneralizationLittle Albert
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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 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

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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

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• Reliable signal? Informative and contingent

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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

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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

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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
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Classical Conditioning

• Goes awry
• Normally neutral stimulus becomes signal of
  negative CR

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Nausea Conditioning among Cancer Patients
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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)

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Siegel (1977, 1983)

• Demonstrated that classical conditioning
  principles might be in effect during
  drug-injecting episodes
• Possible reason for overdoses

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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)
•  

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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

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Atkinson, 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

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Atkinson, 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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Operant Conditioning

• Law of Effect (Thorndike)
• Rewarded behavior is repeated
• Operant Conditioning
• behavior strengthened if followed by
  reinforcement
• behavior weakened if followed by punishment

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Trial-and-error learning
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A cats Behavioral Repertoire (here, for escaping
an enclosed space)
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Operant Conditioning

• Operant Behavior
• voluntary behaviors
• operates acts on environment
• Behavior ? Consequences
• Reinforcer
• any event that follows behavior AND
  strengthens it

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Operant Conditioning

• B.F. Skinner (1904-1990)
• Built on Thorndikes Law of Effect
• Discovered schedules of reinforcement

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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

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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

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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

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Schedules of Reinforcement
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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

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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

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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

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Schedules of Reinforcement

• Variable Interval (VI)
• behavior is reinforced at unpredictable time
  intervals
• produces slow, steady responding
• like pop quiz!

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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

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Discrimination Demo

• 1 for getting right answer, owe 1 for wrong
• Mother Father Friend (triangle)
• - Son Sister Uncle

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Shaping

• Can leave lab once rat touches lever three times
  in 10 seconds

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Shaping

• Successive approximations to goal behavior

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Punishment

• An aversive event that decreases the behavior
  that it follows

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Reinforcement Punishment

• Positive reinforcement
• Negative reinforcement
• Positive punishment
• Negative punishment

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Operant Conditioning
Positive negative reinforcement Positive
negative punishment
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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

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Operant vs Classical Conditioning
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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 Chomskys critique
• marked the end of behaviorism as the dominant
  paradigm of psychology

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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  
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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 Chomskys critique
• marked the end of behaviorism as the dominant
  paradigm of psychology

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Observational Learning

• Bobo Doll study (Bandura)

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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 Chomskys critique
• marked the end of behaviorism as the dominant
  paradigm of psychology

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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

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Is brain-behavior behavior?

• If so, it can be conditioned just like other
  behaviors
• Two current fields Neurotherapy and
  Brain-Computer interfaces (BCI)

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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

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INTRA-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.

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Biofeedback

• Neal E Miller trained autonomic functions
• Rats control heartrate to get water
• Dogs salivate to get food

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/- 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

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Two forms of Biofeedback PNS CNS (peripheral
and central)

• Peripheral Body (skin) temperature, GSR (skin
  conductance), muscle (EMG), heart rate
  variability, breathing, pulse

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CNS Central Nervous System biofeedback
When you become aware of your own brain
activityyou can change it