Extinction Flashcards
What does extinction show us?
Extinction shows how durable learning is (we don’t forget) and shows how adaptable our bvr is
What is learning?
• Change in behaviour as a result of experience
o Adaptive: behaviour is plastic and flexible to suit the environment in which we find ourselves
What is non associative learning?
o Habituation, sensitisation – changes to make our experience more suited to the surroundings
no associations made between cues or bvrs and outcomes
What is associative learning?
o Learning to predict relationships between events, actions and outcomes.
o Allows us to seek out and obtain rewards and avoid situations that are dangerous
What is classical conditioning?
Learning that an event / object / context predicts a particular outcome
no particular bvr input require from the subject to get the outcome
What is operant conditioning?
Learning that particular actions will result in particular outcomes
dependant on the bvr of the subject, subject has to elicit a specific response to get an outcome
What is a reinforcement and a punishement?
Reinforcement = an event that increases the likelihood of repeating the response that preceded it.
Punishment = an event that decreases the behaviour that precedes it.
What is the prediction error theory?
• The amount of learning that will occur in any one trial depends on how surprising the unconditioned
stimulus is
If smtg occurs that you werent expecting, you learn a lot more about the conditions you were in
• The difference between the expected outcome and the actual outcome.
WHAT HAPPENS IF THE EXPECTED OUTCOME IS OMITTED?
NEGATIVE PREDICTION ERROR
What is extinction?
decrease in the conditioned response as a result of CS-alone presentations
What are 2 theories of extinction?
• Unlearning or erasure of the CS-US association
• New learning of a second, competing association that inhibits the expression of the original association (not unlearning)
What is classical reinstatement?
“REMINDING” THE SUBJECT ABOUT THE STIMULUS
1) Trained to fear tone
2) Extinguish so dim fear
3) Reminder shock without CS (no learning) => retrieval of fear
The reminder is context dependent (has to occur in the same context as initial con) => contextual cues are very imp
What is classical renewal?
EXTINCTION IS CONTEXT SPECIFIC
Put in new env for extinction
If put back in env of initial con, show much more fear than in extinction env
Renewal is a very robust effect: if extinguish in a diff context then its like never extinguished at all
If extinction context matches retrieval context = unlikely to get renewal
Extinction is context specific – removal from extinction context –> renewal
Acquisition is less context specific – will generalise across contexts
What is classical spontaneous recovery?
EXTINCTION DISSAPATES OVER TIME
There’s a bit of aug in responding in animals who are tested immediately but its ntg compared to the aug in responding 6 days later
Maybe time is a context
Over a period of time, the discrete features of context generalise, makes more likely to retrieve initial association which is less context specific than extinction
What does extinction do?
It causes ambiguity
The meaning of the Tone depends on its context; In some contexts, CS predicts US and in others it predicts the absence of US
Inhibitory association only occurs if both the Tone and Context are present.
Context helps to disambiguate the situation: will I or wont I get shocked?
Why is the conditioned response not erased after classical extinction?
Extinguished fear responses often recover without any additional CS-US retraining.
This is because extinction learning and memory is closely tied to the context where extinction occurred.
The original CS-US memory is NOT context dependent
What is the clinical significance of classical extinction?
- To understand how we learn about our environment, to understand how we learn about changes to our environment.
- To understand anxiety.
Exposure therapy is extinction.
What are 3 caveats of using classical extinction in a clinical setting?
• Extinction is context specific
• Learned behaviour reinstates following brief exposure to the unconditioned stimulus
• Extinction dissipates over time
Often following clinical intervention theres still aniety bc the initial fear associations arent erased and expression of extinction is much more labile
What are the age differences in classical extinction?
Reinstatement (reminder of US should cause aug in bvr): preado aug bvr but babies dont same thing for renewal and spontaneous recovery
Reinstatement, renewal and spontaneous recovery is not presence in babies bc the circuitry necessary for extinction is not fully dev in juveniles (flexibility of bvr is not present yet), they cant retrieve the initial associations
Adolescents show poor extinction retention
What are the sex differences in classical extinction?
• Some evidence for sex differences
• Not always
• Fluctuating hormones may mediate sex differences
• If considered by estrous phase:
• Proestrous (high estradiol) = facilitated extinction
• Metestrus (low estradiol) = impaired extinction
- Hormone supplements/blocks can facilitate/impair extinction
• In females
• And males
• Suggests that hormone cause changes to extinction rate
Males given estradiol inhibitor had impaired extinction recall but showed good extinction recall when given estradiol with the inhibitor
In adolescents the effect is the opposite!
Proestrous and Disestrous (high estrogen) = impaired extinction.
How is operant conditioning different from Pavlovian conditioning?
In contrast to classical con where the outcome depends on the experimenter, the outcome in operant con depends on the bvr of the subject
How does operant extinction work?
- Conditioning: bvr is reinforced, aug in learned bvr that is reinforced
- Extinction: take away reinforcer, dim in responding, no change in inactive lever
- Reinstatement: extinction isnt the erasure of the 1st association but the formation of a new one bc we can retrieve the 1st one
What is the clinical significance of operant extinction and its 5 problems?
Reduce unwanted behaviours e.g….
• Conduct disorder and other disruptive behaviours
• Substance use disorder, gambling use disorder
Extinction and reinstatement can help understand relapse in drug seeking (understand the neurocircuiterie)
Problems with extinction as an intervention
• What is the reinforcer?
• Are there more than one reinforcers?
• What is being extinguished?
• Extinction burst
• Extinguished behaviours can return.
What is reinstatement in operant extinction?
Retrieval of extinguished response as a result of the reinstatement of the reinforcer
Reinforcer itself acts as a “discriminative stimulus”/signal that pellets were available
Each time food is give, theres an aug in responding but declines over time bc just bc get one pellet, dont get more if press
