L19 - Applications of learning Flashcards
Pavlovian-to-instrumental transfer (PIT)
Pavlovian cues can enhance instrumental responding to gain a reward despite each response being trained separately.
E.g., even though the light and tone have never been paired together, they somehow associate the positive outcome together.
Lovibond and Colagiuri
Experiment showing PIT
Tried to create a human skinner box, Press button a certain number of times to get chocolate, Different light paired with chocolate.
- Present light and allow participant to respond,
- Instrumental extinction, after 2 phases extinguish button response, button leads to no reward, reduce responding to more easily see effects
- Blue green light what happens?
- Evidence in humans that blue light leads to more button pressing
Why is the extinction phase introduced and issue with it?
Given to avoid ceiling effect, which occur if baseline responding was too high and no facilitation to CS+ would be detected (even is there is an excitatory association)
Issue: Removing ceiling effects doesn’t represent real world
Specific PIT
When a reward cue elicits motivation to respond to receive a specific reward (outcome specific)
General PIT
When a reward cue energies motivation to respond generally (outcome non-specific)
Colagiuri and Lovibond
- Same test but no extinction phase
- No differences in baseline, increased responding to blue light as they are paired before, also actual consumption went up (overconsumption effects in real life)
Evidence that Pav cue enhance voluntary responding to real rewards even when tested under instrumental reinforcement
Corbit et al specific pit experiment
R1 - left lever press, O1 food pelet
R2 - right lever press, O2 sucrose
S1 - noise, food
S2: light, sucrose
Instrumental extinction of 2 actions
S1 leads to more responding of R1
Corbit et al general pit experiment
more abstract, under s3 stimulus paired with outcome but not specific response, responds to both
- Presenting s3 will engage motivation but without specific motivation to which response
R1 and R2 food and sucrose
S3 bell to different food and s4 to nothing
S3 presented press both levers, nothing for S4
Drug cues form Pav associations that can induce-drug seeking in a variety of ways (name 3)
- Increasing hedonic value of drug cues leading to more time spent in drug contexts (e.g. conditioned place preference)
- Inducing a motivational state to work to obtain the drug (Palv-to instrumental transfer)
- Inducing CCRs that produce a craving-like state and lead to behaviour aimed at escaping the aversive withdrawal like symptoms (opponent process model)
Cue exposure therapy
Aims to use extinction to diminish the CS-US associations that encourage drug taking by presenting drug cues without subsequent access to the drug.
O’Brien cue exposure therapy experiment
Abstinent cocaine addicts exposed to drug cues (audio, visual) without access to cocaine
- Test what happens if we repeat exposure to cues
- Evidence of extinction, craving goes down, reported feelings of high goes down, craving strongest but goes down overtime
- Exposure reduces craving overtime, physiological too
Why does cue exposure therapy not work (relapse)?
Fails because of new learning that overrides phenomena:
- ABA renewal - extinction in a second context fails to eradicate responding in the original context
- Responding in renewal context is high, extinction is only strong in context it was extinguished
Bezzina (2014)
- ABA renewal tested, red light responding that you aren’t getting in AAA
- Renewal due to new context
Context specific
Conditioned Nausea
nausea to stimuli associated with time of nausea eg nurse
Quinn et al
§ One group pre-exposed to device
□ Does this pre-exposure undermine conditioning, does it produce weaker conditioned nausea effect
Results: Pre-exposure get no conditioned nausea, nice result!
Overshadowing and Conditioned nausea
Overshadowing: Salient S paired with less salient S
- So perhaps conditioned nausea to the chemo context can be overshadowed by other cues
- Overshadowed group much less nausea and takes longer, can reduced conditioned nausea