Factors Influencing Conditioning

1
Factors Influencing Conditioning
1

• CS and US Intensity, and Attention to the CS
• Temporal relationship
• Predictiveness
• Preparedness
• Redundancy

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CS Intensity Affects Rate
2
Strong CS
CS
US
Weak CS
cs
US
3
Suppression and CS Intensity
3
4
Another CS Intensity Effect
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Overshadowing the more salient CS wins if two
CS are trained in compound
Group Stage 1 Test Overshadow Ax ? US
cr Control ax? US CR
Note Undercase letters stand for weak intensity
CSs
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CS Attention and Latent Inhibition
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Group Phase 1 Phase 2 Test Experimental
X,X,X X?US cr Control ---- X?US
CR

• Because the CS is a benign stimulus it will lose
  the capacity to command ATTENTION if preexposed
• Little x will eventually produce a robust CR

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The Influence of Intensity

• Exception The effect of the CS on the intensity
  of the CR is sometimes seen when the subject is
  exposed to both the high and the low intensity
  CSs which are individually paired with the US on
  separate trials.

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US Intensity Affects Rate and Asymptote
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Strong US
CS
US
Weak US
CS
us
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Suppression and US Intensity
8
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Temporal Relationship
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CS
Delay
US
Trace
CS
US
Simultaneous
CS
US
Explicitly Unpaired
CS
US
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Time Conditioning

• No distinctive CS
• UCS is presented at regular intervals
• The passage of time is CS
• To determine whether conditioning has occurred,
  the UCS is omitted and the strength of the CR is
  assessed

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Indirect Conditioning
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• Many stimuli develop the ability to elicit a CR
  indirectly
• i.e., a stimulus that is never itself paired with
  a UCS comes to elicit the CR
• Two important ways for this to happen are
• Higher-order conditioning
• Sensory preconditioning

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Higher-Order Conditioning
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Group Stage 1 Stage 2 Test Result HOC A?US
B?A B? cr Control C?US B?A B?
ziltch
HOC A modest CR develops to B because if signals
a reminder for the US, namely, the already
conditioned A.
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Sensory Preconditioning
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Group Stage 1 Stage 2 Test Result SPC B?A
A?US B? cr Control B?A C?US
B? ziltch
SPC A modest CR occurs to B at test, because it
signals the A, which is now a reminder for the
US.
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CS-US Preparedness
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From Garcia Koelling, 1966
Back
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Are forward pairings enough to generate a CR?
No!!!!!!!!
Predictiveness of the CS
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Predictiveness of the CS

• Predictiveness the consistency with which the CS
  is experienced with the UCS, which influences the
  strength of conditioning.
• The pairing of a CS and UCS does not
  automatically ensure that conditioning will occur.

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A Contingency Experiment
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CS
US
Chance of US per CS 2/4 .5
Chance of US outside CS
0/10 0
Positively Correlated
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A Contingency Experiment
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CS
US
Chance of US per CS 2/4 .5
Chance of US outside CS
5/10 .5
Uncorrelated
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A Contingency Experiment
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CS
US
0/4 .0
Chance of US per CS
Chance of US outside CS
5/10 .5
Negatively Correlated
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Its a little like
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• Animals are scientists, trying to make
  cause-gteffect predictions.
• trying to determine whether the US is
  contingent on the CS
• lots of pairings in the zero contingency group

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Quantifying
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• p(USCS) proportion of CS trials with a US
• p(USno CS) proportion of background only
  trials with a US
• Dp p(USCS) - p(USno CS)

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Some Examples
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• p(USCS)

• p(USno CS)

Dp

• 20/20 1.0
• 15/20 .75
• 10/20 .50
• 10/20 .50
• 0/20 0

• 0/60 0
• 6/60 .10
• 30/60 .5
• 45/60 .75
• 60/60 1.0

• 1.0
• .65
• 0
• -.25
• -1.0

1
2
3
4
5
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1
1.0
Positive
2
P(US/ CS)
3
4
Negative
5
0
1.0
P(US/no CS)
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Redundancy
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Group Stage 1 Stage 2 Test Result Blocking
A?US AB?US B? cr Control AB?US B?
CR
Blocking Limited or no acquisition of a CR to a
second conditioned stimulus, B, when it is
introduced alongside an already conditioned first
conditioned stimulus , A.
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Extinction Paradigm

• Extinction of a conditioned response when the
  conditioned stimulus does not elicit the
  conditioned response because the unconditioned
  stimulus no longer follows the conditioned
  stimulus

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Loss of the CRs

• Hull considered the extinction process to be a
  mirror image of the acquisition.
• It is not. One reason for faster extinction than
  acquisition is that extinction alters the
  motivation level via omission of the UCS.
• Decline is also caused by the development of
  inhibition rather than erasing the first-learned
  CS-US association.
• So, the CS is part excitatory and part
  inhibitory after the end of the last extinction
  trial

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Evidence for new learning

• A rest period after the last extinction trial can
  produce spontaneous recovery. More rest causes
  more spontaneous recovery.
• If extinction takes place in a different context
  than acquisition, a return to the original
  context of acquisition causes the immediate
  return of the CR (called ABA renewal).

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Duration of CS Exposure

• As the duration of CS-alone exposure increases,
  the strength of the CR weakens
• Shipley found total duration of CS alone
  exposure, not number of extinction trials is
  critical, but subsequent research has not always
  confirmed his result.

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Exposure Therapy
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• To increase sustained abstinence, some therapists
  have used a technique that involves exposing the
  addict to as many drug related cues as possible
  during extinction.
• Withdrawal responses and drug cravings decrease
  as a result of exposure to drug-related cues.

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Systematic Desensitization
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• Developed by Joseph Wolpe
• Used to inhibit fear and suppress phobic behavior
• SD uses counterconditioning and Wolpe based it on
  three lines of evidence

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Systematic desensitization
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• Involves performing deep muscle relaxation
  techniques while first imagining, and then
  experiencing, anxiety-inducing scenes
• Relaxation involves cue-controlled relaxation, a
  conditioned relaxation response that enables a
  word cue (e.g., calm) to elicit relaxation
  promptly

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Stages
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• Systematic desensitization consists of four
  separate stages
• 1) construction of the anxiety hierarchy
• 2) relaxation training
• 3) counterconditioning the pairing of
  relaxation with the feared stimulus and exposure
  therapy
• 4) assessment of whether the patient can
  successfully interact with the phobic object

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Hierarchies
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• Hierarchies may be either
• Thematic scenes all related to a basic theme
• Spatial-temporal based on phobic behavior in
  which the intensity of the fear is determined by
  distance either physical or temporal