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Behavioral Learning 1

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Teaching relaxation and breathing exercises alleviate the physical symptoms ... self-injurious behavior with relaxation. Relaxation drugs are often used ... – PowerPoint PPT presentation

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Title: Behavioral Learning 1


1
Behavioral Learning (1)
  • ...any technology of control will be bought,
    adapted, and monopolized by the powerful for
    their own not always benevolent purposes.

2
Why Study Behavioral Learning?
  • Train a pet
  • Clinical significance
  • Control your friends (?)

3
Habituation
  • The simplest of all behavioral learning forms
  • A decline in the tendency to respond to familiar
    stimuli
  • The faster we habituate the faster we recover and
    the slower we habituate the slower we recover
  • Why habituate? Darwin would say...It narrows the
    range of stimuli that elicit escape reactions,
    thus freeing resources to focus on new stimuli
    that might be dangerous

4
Habituation to Conditioning
  • In habituation, one learns a familiar event but
    doesnt learn to associate it with anything
  • Association is the basis for Conditioning
  • Ivan Pavlov (1849-1936) is credited with the
    advancement of conditioning

5
The Conditioned Reflex
  • Repeated bell-food pairings led to salivation
    when the bell was presented alone
  • Pavlov described this phenomena in terms of
    unconditioned and conditioned reflexes
  • Unconditioned stimuli (US) is normally associated
    with an unconditioned response (UR)
  • A conditioned stimulus (CS) is paired with a (US)
  • Giving a number of presentations the (CS) will be
    perceived as a (US) and lead to a conditioned
    response (CR)

6
Extinction
  • The (CS) will gradually disappear of repeatedly
    presented without being enforced
  • Reconditioning can occur with fewer reinforcement
    trials
  • Thus, the learning wasnt completely gone but
    rather masked

7
Generalization
  • Will a response be given only if the stimulus is
    identical?
  • A dog conditioned to a tone of 1000 Hz will give
    a response when the tone is 900 or 1100 Hz
  • However, there is a generalization decrement such
    that a weaker (CR) will be elicited if not the
    original (CS)

8
Discrimination
  • Even if a stimulus is similar we may not want to
    generalize our behavior to it (may be dangerous)
  • Thus, we need to discriminate
  • A dog is conditioned to a black square. The dog
    will also salivate to a gray square
    (generalization). After withholding
    reinforcement to the gray square the dog will
    gradually discriminate and only respond to the
    black square

9
Blocking
  • When a stimulus is redundant (information that an
    organism already has) it will not become
    connected to the CS
  • Group I - (stage 1) noise-shock, (stage 2)
    noiselight-shock, (test) light alone, (result)
    no conditioned fear
  • Group II - (stage 1) no stimulus, (stage 2)
    noiselight-shock, (test) light alone, (result)
    conditioned fear
  • Once theyve discovered a stimulus that signals
    the US they no longer connect other stimuli to
    the US
  • Proactive Interference?
  • Bases for Prejudice

10
The Drug Effect
  • Opiates (morphine or heroin) have effects such as
    euphoria, relief from pain, and relaxation (UR)
  • The needle becomes the CS
  • The sight of the needle produces depression,
    restlessness, and increased sensitivity to pain
    thus increasing the likelihood of an overdose
  • The CR is actually the opposite of the UR
  • Given a different environment the Drug Effect is
    weaker

11
Classical to Instrumental Conditioning
  • Instrumental conditioning is also called operant
    conditioning
  • Differences
  • Instrumental - reinforcement (reward) depends
    upon the proper response. The response must also
    be selected from a sometimes large set of
    alternatives
  • Classical - the US is presented regardless of
    behavior

12
Instrumental Conditioning
  • Edward Thorndike (1874-1949) is credited with
    Instrumental (Operant) Conditioning
  • The idea was developed by observing hungry cats
    in a Puzzle Box
  • Through random movements the cat would hit the
    trigger to open the door
  • Give enough trials and the cat would trigger the
    door right away

13
Law of Effect
  • According to Thorndike, some responses get
    strengthened and other weakened as learning
    proceeds
  • The response determines whether the tendency to
    perform is strengthened or weakened
  • If followed by a reward it will be strengthened
    if followed by a the absence of reward (or
    punishment) it will be weakened
  • No intellectual process required

14
Skinners Distinction
  • In Classical, the animals behavior is elicited
    by the CS (from the outside)
  • In Instrumental, reactions are voluntary (emitted
    from within)
  • Tendencies for reactions are strengthened or
    weakened
  • Measured response rate with the Skinner box

15
Skinners Terminology
  • Appetitive Stimulus Positive Reinforcement
  • Aversive Stimulus Negative Reinforcement

16
Shaping
  • Method of Successive Approximations
  • Start by reinforcing a general behavior
  • Change the reward placement so there needs to be
    a more specific behavior
  • Change the reward placement so there needs to be
    another more specific behavior
  • Your dog puts the paper on the table

17
Partial Reinforcement (Schedules)
  • Fixed-Ratio Schedule - produce a specified number
    of responses for every reward
  • Variable-Ratio Schedule - reinforcement comes
    after a certain number of responses, but that
    number varies irregularly
  • Fixed-Interval Schedule - Reinforced after a
    certain interval (i.e. every 2 min)
  • Variable-Interval Schedule - Interval varies
    irregularly around some average period (i.e. 4
    min)

18
Question
  • What kind of reinforcement is better? Partial or
    Continuous
  • Both receive the same number of trials but no the
    same number of reinforcements
  • Partial seems to be better, but which schedule?
  • Ratio engender greater resistance to extinction
    if they are variable

19
Aversive Conditioning
  • What is the reward in aversive reinforcement?
  • It is not absence of the aversive condition that
    is the reward, but rather the absence of the
    aversive condition when it is expected

20
Behavioral Learning (2)
  • Cognitive Interpretations

21
Question
  • What are test animals actually learning? Simple
    associations or causal links?
  • Behaviorists - learning is in terms of
    associations, either between events, or action
    and consequences. Learning can only be achieved
    by doing, thus performance is indispensable
  • Cognitive psychologists - learning is in terms of
    causal links

22
Cognitive View - Classical Conditioning
  • Hilgard (1938) - Two lights (left right), when
    one light became brighter there as an airpuff
    delivered to one eye causing a blink.
    Conditioning occurred.
  • When subjects were told that no airpuff would
    result given a right light the conditioning in
    that right eye was immediately extinguished
  • Instruction works thus, subjects need to be
    aware of the stimulus-response relationships

23
Support for Cognitive View (2)
  • Gleitman (1963)
  • Rats were ferried from one end of a large room to
    another in transparent trolley cars
  • Latter tests showed that they had learned
    something about the general features of the room
    even thought they had not performed any relevant
    responses

24
Relation Between CR and UR
  • Are the two the same?
  • Pavlov believed that they are the same
  • However, his own data show that they look the
    same but under are not identical
  • There was a greater amount of salivation measured
    under UR conditions compared to CR conditions
  • Thus, the CS serves as a preparatory signal but
    does not become a substitute for it (cognitive
    link)

25
Cognitive View - Instrumental Conditioning
  • Evidence for Act-Outcome Associations
  • Rats were run in an enclosed maze that had a
    black end-box on one side and a white end-box on
    the other side, both had food
  • Later, rats were placed into each box w/out
    running the maze. In the black box they found
    food and in the white box they were shocked
  • When put back in the maze they ran to the black
    box
  • The rats combined two experiences this doesnt
    fit into the instrumental learning framework

26
Clinical Considerations
  • Maladaptive Learning Application of the
    Conditioning Theories

27
Learned Helplessness
  • How do people reach the state of helplessness and
    depression?
  • Experiment - Two groups of dogs who received
    electric shocks. Dogs were linked such that
    Group 1 could turn off the shock by pushing a
    panel. Group 2 had no power but rather received
    the same shocks as Group 1 (same fate).
  • Given a new situation Group 1 dogs learned to
    push the button quickly. Group 2 dogs ended up
    becoming passive. They lay down and took
    whatever shocks were delivered
  • Group 2 dogs had learned helplessness

28
Learning Fear
  • While fear and phobias may be generated by
    conditioning in some cases, there seems to be
    more at work
  • Fear of the Dentist may be conditioned but fear
    of snakes and spiders may be cause by a cognitive
    association
  • Someone tells you a story of a tick that ate
    someones brain will make you fear ticks
  • Overcoming fear and depression are difficult

29
Treatment Methods
  • Desensitization - brief approaches
  • Modeling - Therapist approaches object then
    subject
  • Flooding - Rapid prolonged approach to the
    stimulus
  • Operant Shaping - Rewarded for a steady approach
    to object

30
Treating Panic Attacks
  • Behavior modification has been helpful in
    treating panic attacks
  • The problem is a feedback loop between the
    initial chance symptom and the patients fearful
    interpretation of it
  • Teaching relaxation and breathing exercises
    alleviate the physical symptoms

31
Treating Self-Injurious Behavior
  • Maladaptive behavior is often associated with
    anxiety (caused by need for attention, feeling of
    vulnerability, confronting difficulty...)
  • Replace self-injurious behavior with relaxation
  • Relaxation drugs are often used (nitrous oxide or
    anesthetic)
  • Thus, relaxation becomes associated with anxiety

32
When Conditioning Fails
  • Token economies have been experimented with for a
    number of years
  • Rewards for good behavior are tokens which can be
    exchanged for things
  • Often subjects will not perform unless directly
    rewarded. Thus, behavior is conditional
  • In real life rewards are not always given for
    being good

33
Question
  • Why dont we use conditioning more often in
    humans?
  • Why does conditioning often fail in human
    subjects?
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