PSY402 Theories of Learning

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PSY402Theories of Learning

• Chapter 3 (Cont.)Indirect ConditioningApplicatio
  ns of Conditioning

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Midterm on Tuesday

• Use my overheads to identify main points for
  studying.
• Important terms are shown boldface in the
  textbook.
• Learn names only of people talked about in a
  whole section (e.g., Watson), not every studys
  author.
• Dont skip the figures and graphs.

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Studying for the Exam

• Try to get basic principles straight.
• What effect does a stronger UCS have, what effect
  do more pairings have?
• Identify UCS, CS, UCR CR in an example, these
  are defined on pg 61.
• Know the different conditioning paradigms on pg
  70 which works best.
• Practice questions are on the Klein text website
  (link on class webpage).
• Study the Section Reviews in the book.

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Predictiveness of the CS

• Predictiveness refers to how reliably the CS is
  associated with the UCS.
• When two or more CSs are present, only the most
  reliable elicits a CR.
• When the CS occurs with the UCS more often than
  the UCS occurs alone, conditioning occurs.
• A CS alone weakens conditioning.

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Blocking

• Presence of a previously conditioned CS (existing
  predictive cue) prevents conditioning of a new
  CS.
• Parent threats presence of fear of the parent
  prevents acquisition of fear to another stimulus.

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More learning
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Higher-Order Conditioning

• A new stimulus (CS2) acquires the ability to
  produce a CR because it is paired with another CS
  (CS1).
• The CR to CS2 is weaker than to CS1 50 as
  strong.
• Higher-order conditioning is difficult to
  accomplish because conditioned inhibition also
  arises.
• More pairings result in inhibition.

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Sensory Preconditioning

• When two stimuli are associated with each other,
  if one becomes a CS, the other will become a CS
  too.
• Dog and neighbor example.
• To get the strongest CR
• Timing is important first CS must precede
  second CS.
• Only a few CS-CS pairings to prevent learned
  irrelevance.

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Vicarious Conditioning

• Berger people hearing a tone and watching
  another person be shocked acquired a fear
  response.
• Watching another person fail at a task can induce
  a stress response.
• Monkeys can acquire vicarious fear responses to
  objects or snakes.
• Arousal is needed for conditioning.

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Contemporary Theories

• Classical Conditioning
• Nature of the CR stimulus substitution theory,
  SOP and AESOP theory
• Predictiveness of the CS Rescorla-Wagner
  associative model, comparator theory, attentional
  theory, retrospective processing approach.

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Stimulus-Substitution Theory

• What is the nature of the CR is it just the UCR
  or is it different?
• Pavlov stimulus-substitution theory
• The CS stimulates the same areas of the brain as
  the UCS, producing the same response.
• Activation of CS with UCS establishes neural
  connection between brain areas.

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Conditioned Opponent Response

• The CR and UCR are often different
• CR of fear is different than UCR of pain.
• Siegel best evidence of difference
• Morphine (UCS) produced analgesia, reduced pain
  (UCR)
• Light or tone (CS) produced hyperalgesia,
  increased pain (CR).
• Rats remove paws from heat quickly with CS,
  slowly with UCS.
• Insulin (glycemia) works the same way

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Drug Tolerance Overdoses

• Elimination of a CS results in a stronger
  response to the UCS, drug.
• Extinction of responding to environ-mental cues
  strengthens drug response
• Changing the context in which a drug is
  administered increases response to the drug.
• Novel environment does not elicit an opponent CR.

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SOP Theory

• Sometimes Opponent-Process theory (SOP)
  explains why CR varies.
• UCS elicits primary A1 (fast) and secondary A2
  (longer) responses.
• A1 A2 can be same or different.
• Conditioning only occurs to A2 the CR is always
  an A2 response.
• When A1 A2 differ, UCR CR differ.

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SOP Explains Timing Effects

• None of the previous models explain why the
  timing of CS-US matters.
• SOP model requires that both CS and UCS be in the
  A1 stage for learning to occur.
• With delay more elements of CS decay from A1,
  becoming A2.

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Activation of a memory node in SOP theory
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Conditions during delay conditioning
Learning occurs only for the elements whose A1
stages overlap
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Conditions during trace conditioning
Without overlap, no conditioning occurs
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Conditions during backward conditioning
Inhibition is conditioned because the CS A1
overlaps US A2 stage
CS comes after the US
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Two-Phase Reactions

• Shock results in
• A1 -- Initial agitated hyperactivity
• A2 -- Long-lasting hypoactivity (freezing)
• CER (fear) elicited by CS is A2
• Morphine results in
• A1 sedation, analgesia hypoactivity
• A2 hyperactivity two hours later hyperalgesia
  (greater pain sensitivity)
• CR elicited by CS is A2 (hyper)

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Affective Extension of SOP Theory

• Why do different A2 responses have different
  optimal CS-UCS intervals?
• Two distinct UCR sequences activate distinct A1
  A2 sequences
• Sensory
• Emotive
• These distinct sequences can have different
  strengths, time scales (latencies), or eliciting
  CSs.

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Faster
Slower
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Rescorla-Wagner Theory

• There is a maximum associative strength between
  CS and UCS.
• UCS determines the limit
• Strength gained on each training trial depends on
  prior training.
• More learning early, less later on
• Rate of conditioning varies.
• Conditioning of a CS depends on prior
  conditioning to other stimuli.

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UCS Preexposure Effect

• If the UCS is encountered without the CS prior to
  pairing of the two, less learning occurs.
• UCS becomes associated with other environmental
  stimuli (without CS).
• Since there is a limit to association strength,
  some is drained off by such prior associations.
• CS-UCS association is weakened.

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Problems with Rescorla-Wagner

• Overshadowing salient cues have more
  associative strength.
• Sometimes a salient cue potentiates another cue
  instead of overshadowing.
• Garcia says cues are indexed.
• R-W says cues are seen as unitary stimulus.
• Unclear which explanation is correct.

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More Problems

• CS preexposure effect appearance of CS without
  UCS prior to learning weakens learning.
• Shouldnt have any effect according to
  Rescorla-Wagner theory, but it does.
• Cue-deflation effect extinction of a more
  salient cue enhances learning for the less
  salient cue.
• Should be no change according to R-W.

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Comparator Theory

• If two CSs are associated, extinction of one
  should reduce responding to the other.
• Sometimes true, other times not.
• CS-UCS associations exist for many stimuli but
  are exhibited only for the strongest.
• Comparator theory says the CSs are judged in
  relation to each other.

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Organisms might learn about elemental or
configural CS nodes
Wagner Brandon
Pearce
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Attentional View

• Mackintosh learned irrelevance occurs during
  preexposure of CS.
• Animals exposed to a novel stimulus exhibit an
  orienting response.
• No orienting with preexposure.
• Habituation results in failure of conditioning
  no attention is paid to a habituated stimulus.
• Pairing of CS/UCS in novel context results in
  learning.

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Retrospective Processing

• Most theories assume the level of responding will
  be constant after learning.
• Baker Mercier suggest association can change
  after learning.
• Retrospective processing CS-UCS contingency
  reevaluated after learning.
• Backward blocking support for theory
• Suggests animals have mental representations,
  memory for events.

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Applications of Conditioning

• Treatment of phobias
• Systematic desensitization
• Treatment of addictions
• Elimination of conditioned withdrawal reactions
• Enhancement of drugs used to treat immune system
  disorders
• Lupus, AIDS

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How a Phobia Works

• A phobia is an unrealistic fear.
• A learning experience causes fear to become
  associated with a neutral stimulus.
• Avoidance prevents extinction.
• The stimulus is generalized.
• Eventually, too many experiences must be avoided
  and a persons functioning is impaired.

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Systematic Desensitization

• Wolpe applied ideas from classical conditioning
  to treatment of phobia.
• Reciprocal inhibition an organism can only feel
  one emotion at a time.
• Mary Cover Jones used counterconditioning to
  extinguish fear.
• Cats could be counterconditioned using food.

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Clinical Procedure

• Construct an anxiety hierarchy.
• Teach a relaxation response.
• Cue-controlled relaxation.
• Counterconditioning pairing of relaxation with
  imagined feared stimuli, starting with least
  scary.
• Assessment of whether the treatment worked
  interacting with the feared stimulus.

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Effectiveness of Desensitization

• Wolpe reported 90 success rate, compared to 60
  for psychoanalysis.
• 12-29 sessions
• Relapse after 1-3 yrs easily treated.
• Works with a wide range of fears.
• Can also be used with anxiety disorders.

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Limitations on Desensitization

• The client must be able to vividly imagine the
  feared stimulus.
• 10 cannot do this.
• Confrontation of a real rather than an imagined
  object is more effective.
• Difficult for the client to endure the anxiety
  associated with this.

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Virtual Reality Desensitization

• Graded height-related stimuli presented via
  virtual reality were effective in treating
  acrophobia.
• Subjects were able to endure real stimuli after
  virtual treatment.
• Successful in treating spider phobia.

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Treatment of Withdrawal

• Conditioned withdrawal reaction environmental
  cues become associated with withdrawal stage.
• Exposure to cues triggers symptoms.
• Withdrawal motivates substance use.
• Extinction by exposure to environmental cues is
  needed.
• Virtual reality also used to treat addictions.

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Treatment of Immune Disorders

• Lupus, AIDS are immune system disorders.
• Treated using drugs that either boost or suppress
  immune system response.
• Classical conditioning can be used to produce the
  results of such drugs without the side effects or
  cost.

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Immune System Conditioning

• Cyclophosphamide used to induce nausea during
  flavor-aversion learning also immunosuppressant.
• The saccharin-flavored water used as a CS caused
  several rats to die.
• The drug reaction occurred without the drug the
  CS evoked immune system suppression.
• Also works with other drugs.

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Treatment of Lupus AIDS

• Rats given saccharin paired with cyclophosphamide
  had slower lupus progression and lower mortality.
• A girl treated for lupus was able to use half as
  much drug when paired with a distinctive taste
  and smell.
• Sherbet paired with adrenaline enhances immune
  functioning for AIDS treatment.