L2: Classical conditioning part 3 Flashcards
do we need to be aware of the CS?
Conscious expectation in not necessary (Ohman and Soares, 1998)
* Pairing of subliminal images of snakes and spiders with electric shocks
* Increased anxiety response (skin conductance) to subliminal images
Phobia of these animals even if not conscious
when is classical conditioning strongest?
When is classical conditioning strongest?
* It depends on the conditionability of the CS and the US ——-> conditioning
* CS that are relatively intense and salient or novel —-> is
* US that elicits a stronger response (e.g. a stronger shock) ——> stronger
* The organism’s biology has prepared them to associate a particular CS with an US (biological
preparedness)
* E.g. rats and humans find it easier to associate sickness with a flavour, rather than a light or a tone
biological factors?
Biological factors and evolutionary influences on learning
Seligman (1970) : Biological preparedness
* evolved tendency to acquire conditioned
responses to stimuli that have had survival
relevance in our evolutionary past more
easily
* E.g. rats learn more easily to associate
sickness with taste, light+click with pain
Ready to associate light with danger
Sweet taste + electrical shock = acquisition more difficult
Biologically intrinsic properties facillitate classical conditioning.
contiguity?
Contiguity; is it enough for a CS to simply precede a US for a CR to occur? No
Egger and Miller (1962):
* If two signals reliably predict a US, only the one presented first will become conditioned
* It two signals precede a US, one always, the other less so, the reliable signal becomes more conditioned
than the unreliable one
➔ the organism must be able to use the CS to reliably predict whether reinforcement will occur (information
value)
rt:
Simply presenting a CS before a US is NOT enough.
The CS must predict the US reliably for conditioning to be strong.
Organisms prioritize stimuli that provide better predictive value over those that are inconsistent or redundant.
Is pairing of a CS and US sufficient for an association to be learned?
Pairing of a CS and a U :contiguity. In classical conditioning, contiguity is the time interval between the
presentation of the unconditioned and conditioned stimuli.
* Overshadowing (Pavlov, 1927): When using a compound CS (e.g. light and loud noise), the more salient
component is conditioned
(overshadows the cr) e.g: phase 1 - bell ringing. Animal predicts food is coming. If starts using 2nd stimuli like light would it elicit result? No. bell is strong and salient so blocks the learning of the 2nd cs.
Depends on how predictable and how salient something is.
* Blocking (Kamin, 1969)
* The learning process tends to take in the most valid predictors of significant events and ignore the less
useful ones
backward conditioning?
No conditioning occurs
* CS is not informative – does not predict occurrence of US (same as when CS is redundant or unreliable)
But there are exceptions to this rule…
contingency vs contiguity?
Phase 1
* Dogs are trained to jump over a hurdle to avoid an electric shock that
is delivered are regular intervals of 30 sec
Phase 2
* Group 1 (forward conditioning): A 5 sec tone is always delivered
before the shock
* Group 2 (backward conditioning): the dog first experienced the
shock and then the tone (the tone was never followed within 30 sec
by a shock)
* Group 3: Dogs experienced the tone preceding the shock an equal
number of times as they did following the shock
Phase 3
* Dogs were retrained as in phase 1. Then the tone was presented a
number of times.
* How was the behaviour of dogs in each group affected?
- Group 1 (forward conditioning): dogs increase their rate of response
(almost doubled it) → positive contingency (predict tone means shock) - Group 2 (backward conditioning): dogs decreased their rate of
response by about a third → negative contingency
➢ The CR can be several different responses, depending on the
context in which they occur
➢ Negative contingencies as just as informative as positive ones - Group 3: Rate of response was the same
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Rescorla (1966) Did the dogs in group 3 learn nothing?
learned helplesness?
Learned helplessness: a generalised belief that one can do nothing to
terminate or avoid an aversive situation
* It is not caused by the traumatic experience per se, but by the
inability or perceived inability to do anything about it.
* In humans: experienced as depression - reluctance to initiate action
to attain reinforcement or avoid punishment, passivity, withdrawal
Fearfulness
Seligman and Learned Helplessness: Maybe Rescorla was looking at the
wrong kind of behaviour…
Phase 1:
* Group 1: Dogs were shocked while constrained, but could terminate
shock by pressing a panel with their snout
* Group 2: Dogs were shocked while constrained, but could not
terminate shock
* Group 3: Dogs were constrained, but given no shock
Phase 2:
Used escape-avoidance training: response to a tone by jumping the
hurdle terminated the shock
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What did dogs in each group learn?
Phase 2:
* Groups 1 & 3: learned to jump to avoid shock
* Group 2: They became passive. Just took the shock and whined.
Even if a member of this group happened to jump the hurdle and
avoid the shock, this was not repeated.
* These dogs learned in Phase 1 that there was nothing they can
do to avoid the shock
➔ Learning pairing between CS - US is not an automatic, mechanistic
process, but depends on cognitive factors
taste aversion applications?
Gustavson et al (1974) fed coyotes with lamb and rabbit meat poisoned with lithium chloride causing neasea and so they learned to avoid eating livestock whos meat made them ill.
Bernstien and Webster (1980) discovered cancer patients undergoing chemotherapy aquired taste aversions to foods they consume before chemotherapy even the cognitive development of adults that allows them to understand their discomfort is due to therapy rather than say ice cream flavour did not override this conditioning
- Chemotherapy induces post-treatment nausea, as well as anticipatory nausea (Nesse et al., 1980;
Rodríguez, 2013) - “Overshadowing” can be used to help cancer patients undergoing chemotherapy reduce/modify
anticipatory/post-treatment nausea (Stockhorst et al., 1998)
Give strong taste of something, overshadow. Kids become adverted? To this food.
are CRs the same as URs?
CR may be antagonistic or compensatory to the UR ➔ how does this help us
understand tolerance and withdrawal effects, and even overdose, in the
context of drug addiction?
extinction applications?
counterconditioning: treating addiction to alcohol.Counterconditioning is when you replace an unwanted response with a new, conditioned response by pairing the stimulus with something different.
Why is this counterconditioning?
Normally, alcohol might be associated with pleasure or relaxation.
The emetic drug (which induces nausea) replaces that positive response with a negative one (nausea).
Over time, the person is supposed to learn to associate alcohol with nausea instead of pleasure.
Non-adherence – Patients may choose not to take the medication when they want to drink.
Limited clinic supervision – Patients cannot return to the clinic every time they have an urge to drink, making it difficult to ensure consistent use.
Extinction of the conditioned response – Over time, without continued reinforcement, the learned aversion may fade, reducing the drug’s long-term effectiveness.
conditioning theories of phobias and treatment?
Conditioning theory of phobias
Phobia: excessive/intense fear to specific object/situation
* Result from conditioned experiences: association with something traumatic, painful, frightening (Watson
& Rayner, 1920)
* Learned vicariously (observationally)
* Importance of prior experience
* Importance of individual differences
* Importance of biological preparedness
Techniques to treat fear-based disorders in humans
Flooding: forced extinction
* People avoid or escape from frightening experiences
* Fast, but variable results
* Some improve – some get worse (patients forced to avoid something that they intensely fear and avoid)
* High drop out rates
systematic desensitisation?
Systematic desensitisation (Joseph Wolpe, 1958)
* Phase 1: anxiety hierarchy
* Phase 2: Teach patients to relax
* Phase 3:
1. first experience deep relaxation
2. introduce the weakest item in hierarchy
3. Client is asked again to induce relaxation again
4. Client is asked to consider the next item on the list
* With each step, a little bit of the phobic response associated
with the more fearful item in the list extinguishes.
* It is hoped that the client will be able to repeat steps in real
world situation and deal with fears rationally
