Lecture 15: Extinction Flashcards
What is the effect of extinction procedures?
- A decline in responding only following an established Pavlovian or Instrumental association
What is omitted in extinction procedures?
- US or reinforcer
Does extinction cause a reversal of learning?
No, true reversal is nearly impossible
What does extinction of pavlovian/associative/classical responding look like?
- Presentations of CS without the US
- Multiple presentations are almost always necessary in spite of rapidity of some forms of fear conditioning
- Results in reduced responding
What does extinction of operant conditioning look like?
- No longer provide outcome (ex. reinforcer) in response to behaviour
- Extinction is opposite to learning/training
- Learn that reinforcer is omitted, do not work as hard for it
Why is extinction important or even necessary?
- Promote adjustments to behaviour in response to changing environments
- Not many reinforcement schedules remain in effect forever
- Ex. children are praised for drawing crude representation of people in nursery school, not rewarded in high school
- Without adaptation, may not get reinforcer you need/want
What is extinction?
- Active process produced by unexpected absence of reinforcer
- Not erasing previous learning
- New type of S-R association
What is forgetting?
- Passage of time
- Does not require non-reinforced encounters with CS or CR
- Not manipulating or omitting US/reinforcer
What is exposure therapy?
- An extinction procedure where participants are exposed to cues that elicit fear in the absence of the aversive US
- Helps with pathological fears/phobias and drug addiction
- Ex. think about snakes in a safe space; exposure to cues related to drug use to extinguish craving
What are virtual reality techniques used for?
- Allow for more vivid realistic exposure to fearful stimuli when its not possible/ethical to actually expose them to the stimuli
- Ex. PTSD
What are the 2 basic behavioural effects of extinction?
- Target response decreases when response no longer results in reinforcement
- Extinction increases response variability, at least at first
What did Neuringer, Kornell and Olufs discover?
- 3 different responses leads to reinforcer
- Group Var: had to make unique order of responses
- Group Yoke: no requirement to vary key responses
- Variability increased with extinction
- Extinction produced decrease in rate of responding
What is frustration?
- The emotional reaction induced by withdrawal of an expected reinforcer
- Need previous learning history
Ex. attacks other pigeon when reinforcer is withheld - This is a problem in exposure therapy (can lead to aggression)
Ex. kick vending machine when you do not receive food
What is consolidation?
- Retrieval from different long-term memory
- Requires protein synthesis
What happens when anisomycin (which blocks protein synthesis) is added in a memory test?
- No consolidation of pairings
- Not necessarily due to extinction, but could not properly reconsolidate memory
- Need to retrieve memory to form CR
What are 4 things that prove that extinction does not erase original learning?
- Spontaneous recovery
- Renewal
- Reinstatement
- Retention of knowledge of reinforcer
What is spontaneous recovery?
- Behaviour returns after extinction
- 8 day rest period in between
What is renewal of original excitatory conditioning?
- Recovery of acquisition performance
- Contextual cues change during extinction
- Previous experience or neutral labs
- New context disrupts retrieval of memory (fear memory generalizes with acquisition, not extinction)
What is reinstatement of conditioned excitation?
- Different context leads to the same response
- Increase in behaviour with the same (original) context
Why does context matter?
- Context conditioning and summation of excitation (might cause reinstatement)
- Context helps disambiguate the significance of a stimulus that has a mixed history of conditioning and excitation (mixed history leads to more effect of context)
- Conditioning of cues in situation summate with excitation remaining at end
What happens with a mixed history and a change in context?
- Don’t freeze as much
- Initial memory is not as strong
- Contextual cues gain excitatory properties with acquisition
What is retention of knowledge of reinforcer?
- Devaluation should lead to decrease in responding
- Behaviour changes, but the associations are maintained
What are some 7 strategies for enhancing extinction?
- Increase number of extinction trials
- Massed = faster extinction, spaced = stronger extinction
- Immediate = faster extinction, delayed = stronger extinction
- Repeated extinction sessions
- Extinction in multiple contexts
- Present retrieval cues for extinction during test
- Compound extinction
What effect does compounding extinction stimuli have?
- Deepens extinction of stimulus greater than the stimulus that underwent extinction alone
How does previous manipulation affect extinction?
- May take longer to learn extinction
- Ex. Experience with nicotine may lead rats to respond more even without reinforcer
