Flashcards in Lectures 21 - 26 Deck (32):
Describe two applications of food aversion learning
Training coyotes to avoid sheep and training quolls and crocodile to avoid cane toads.
What type of animal can't acquire a food aversion
animals that only eat one safe food e.g. vampire bats
Identify the evidence that CTA is a special type of learning
Stimulus specificity - sickness associated with tastes, but hardly with audio-visual events.
What is long delay learning and is it special to CTA?
CTA occurs when sickness follows many hours after taste. NO, relative lack of interference provides a basis for long delay learning in CTA. Interference from other tastes (overshadowing) can prevent long delay learning, whereas other events are not relevant. Therefore, long delay learning results from the high degree of stimulus specificity.
Describe why one trial learning and resistance to extinction are not special or true properties of CTA.
CTA does have one-trial learning, however so does other kinds of conditioning e.g. fear conditioning. CTA is not resistant to extinction - trials done to substantiate this claim were two bottle choice experiments, where the animal could avoid the taste, therefore avoiding extinction. so the apparent resistance to extinction results from rats avoiding contact with the averted taste.
What were Gracia's 6 original claims as to why CTA was special?
1. stimulus specificity
2. long delay learning
3. one-trial learning
4. resistance to extinction
5. potentiation of odor aversion learning by tastes
6. involves different brain structures
True or false:
1. CTA requires cognition
2. CTA only in upper GT illnesses
3. psychoactive drugs can support CTA
True or Fase:
- We have innate hedonic reactions to odors
Explain your answer
False! the strong withdrawal reflect elicited by pungent odors like sulfur is mediated by the trigeminal system not the olfactory system. because smells constitute a large part of flavors, whether flavors or foods are yummy or yucky, is largely based on learning.
Compare flavour learning in animals and humans
- Both humans and other omnivores show nausea based taste aversion learning but humans can also acquire cognition based aversions.
- social learning is important for acquiring flavour preferences and aversion in both humans and rats
- only humans appear to develop preferences fo some initially highly aversive tastes e.g. quinine and chilli
- humans and rats both acquire preferences for flavours based on association with food or nutrients
- unlike tastes, humans don't have innate preferences to pure odours/flavour.
Is flavour-flavour learning or flavour-calorie learning dependent on motivational state
What effect does pre-exposure to saccharin have on preference for an almond flavour upon exposure to an almond + sucrose solution? Explain.
It increases preference for the almond. exposing saccharin will weaken the sweetness-calorie association, so in stage 2 when almond and sucrose are paired, the animal learns that sweetness of sucrose isn't related to the calories but the almond is. This happened because saccharin caused LI of learning that sweetness of sucrose is the cause of calories.
What effect does pre-exposure of sucrose have on the preference for an almond flavour after upon exposure to an almond sucrose solution? Explain
It will decrease preference for the almond. the pre-exposure phase has sucrose, so the animal will learn the sweetness-calories association. In phase 2, the animals knows that the sucrose has calories, hence doesn't pay attention to the almond.
What implications does the sweetness-calorie association phenomenon have on our diets. (Hint: softdrinks)
non-nutriative sweeteners such as diet coke, weaken the sweetness-calorie association, so that individuals compensate less fully after eating sweet (high-energy) foods.
Compare a placebo vs nocebo effect
placebo effect creates positive expectancies and positive outcomes. Nocebo effect creates negative expectancies and negative outcomes.
Describe some problems with the distinction between placebo and nocebo.
- positive and negative effects simultaneously e.g. drug gives positive effects but side effects
- who defines positive and negative e.g. beer placebo
- what about neutral effects e.g. increase HR
- how well can we access peoples expectancies.
What are some effects that could be mistaken for a placebo effect? (3x2=6)
- natural time corse: spontaneous recovery + regression to the mean
- reporting bias: demand characteristics + criterion shift
- behavioral change: Hawthorn effect + Crum and Lager
Describe the two theories of the placebo effect
1. expectancy theory - suggestion and experience create response expectancies and these response expectancies can produce placebo effects in and of themselves.
2. classical conditioning - through repeated CS + drug US pairings, the context acquires the ability to elicit a therapeutic effect CR in and of itself.
What does each theory of the placebo effect predict about extinction.
- expectancy theory predicts that placebo effects should not extinguish because the occurrence of a placebo effect reinforces the expectancy on which it is based.
- classical conditioning theory predicts that placebo effects with extinguish because presentation of CS alone will weaken CS-US association on which the placebo effect is based.
Are placebo effects be conscious or unconscious? Explain your answer.
Yes, evidence they can be both concious and unconcoius:
Benedetti et al. (2003)
- pain sensitivity (concious) subject to placebo effect. pain sensitivity was in direction of suggestion, even when prior conditioning was in the opposite direction.
- GH (unconscious) level was in direction of suggestion only when prior conditioning was congruent
Conscious processes appear to be driven by conscious expectancies whereas nonconscious processes are not influenced by conscious expectancies only nonconscious conditioning
Do placebo effects extinguish?
no nocebo effects extinguish?
placebo - inconclusive evidence!
nocebo - no!
what effect does PRT have on the placebo effect
placebo effect usually stronger in CRF than PRF but placebo effect extinguishes for CRF whereas PRF is maintained.
Why doesn't the aversive consequences of drinking (i.e. negative reinforcement) e.g. vomiting, reduce drinking behaviour?
timing - bad time less associated with the alcohol then the good time.
What is the difference between wanting vs liking?
Wanting is normally engaged by events of biological importance and through Pavlovian conditioning, neutral cues can acquire incentive value. Liking is controlled by a negative feedback mechanism. Wanting has no negative feedback mechanism.
How can the opponent process model describe tolerance and withdrawal
A process - drugs effect on CNS that induces physiological changes
B process - attempting to maintain or regain homeostasis, the body initiates drug comes
Withdrawl - when A process ceases but B process still present
Tolerance - drug user learns that the best way to stop withdrawal is to make more drug, but this causes the B-state to grow, and user must take more drug to get high
How can the opponent process model account for context-specific tolerance effects?
Certain cues that are reliability associated with the arrival of drugs in the body become associated with the B process, such that these cues elicit an anticipatory B process and so reduce the drugs effect.
What is PIT?
Pavlovian cues can enhance intramental responding to gain a reward despite each response being trained separately.
Give an example of PIT
PIT for chocolate:
- condition blue light with M&M and green light with no M&M
- find that when present cue that is paired with the food i.e. blue light, get more responding.
What is the purpose of extinction in PIT experiments? What is the issue with this?
If you reduce responding, you will then be able to see the facilitation effect of the CS+ - avoid ceiling effects which would occur baseline responding was too high and no facilitation to CS+ would be detected. BUT issue is that it reduces the ecological validity since in real life, the reward is available.
What is the difference between specific and general PT?
specific PIT is when a reward cue elicits motivation to respond to receive a specific reward. General PIT is when a reward cue energies motivation to respond generally.
What is Cue exposure therapy?
Drug cues can induce drug-seeking - cue exposure therapy aims to sue extension to diminish the CS-US associations that encourage drug taking by presenting g drug cues without subsequent access to the drug.
Why does cue exposure therapy often fail?
Extinction is new learning that can override but not erase the previous learning - spontaneous recovery, reinstatement, renewal. Renewal when cues associated with the CS+ from the context.