Extinction and Stimulus controlChapter 8 – Wintersession 2015

Extinction

Extinction The nonreinforcement of a

previously reinforced response, the result of which is a decrease in the strength of that response Extinguished/ partially

extinguished Important to ensure that the

consequence being withheld is in fact the reinforcer that is maintaining the behavior

Possible side effects

When an extinction procedure is implemented, it is often accompanied by certain side effects

Important to be aware of side effects… Can be misleading May be tricked into thinking not have an

effect, but it does

Side effects of extinction

Extinction burst A temporary INCREASE in the frequency

and intensity of responding is first implemented

Increase in variability Extinction procedure can result in

greater variability in behavior

Side effects of extinction

Emotional behavior E.g. frustration

Aggression Particularly

common during extinction behavior

Side effects of extinction

Resurgence The reappearance during extinction of

other behaviors that once had been effective in obtaining reinforcement E.g. repeating something that had earlier

been effective

Depression Low activity Loss of reinforcement

Resistance to Extinction

Resistance to extinction Extent to which responding persists after

an extinction procedure has been implemented

Number of factors can affect resistance Schedule of reinforcement History of reinforcement Magnitude of the reinforcer Degree of deprivation Previous experience with extinction

Factors that affect extinction

Schedule of reinforcement Most important factor influencing

resistance to extinction Partial reinforcement effect: behavior

that has been maintained on an intermittent (partial) schedule of reinforcement will extinguish more slowly than behavior that has been maintained on a continuous schedule (takes longer to “discover” that

reinforcement is no longer available)

Factors that affect extinction

History of reinforcement Generally, the more reinforcers an

individual has received for a behavior, the greater resistance to extinction

Magnitude of the reinforcer Big food pellet vs. small food pellet

Factors that affect extinction

Degree of deprivation The degree to which an organism is deprived of

a reinforcer also affects resistance to extinction Greater the deprivation greater resistance to

extinction

Previous experience with extinction Sometimes sessions of extinction are alternated

with session of reinforcement Greater the number of prior exposures to

extinction, the quicker the behavior will extinguish during subsequent exposure

Distinctive signal for extinction

Extinction greatly facilitated when there is a distinctive stimulus that signals the onset of extinction Discriminative stimulus for

extinction = faster extinction SΔ

Spontaneous recovery Just because a

response has been extinguished, it doesn’t mean it has been permanently eliminated

Reoccurrence of an extinguished response following a rest period after extinction Function of

discriminative stimuli

Differential reinforcement of other behavior

Process of extinction can be greatly facilitated by both extinguishing the target behavior and reinforcing the occurrence of a replacement behavior

More effective than simple extinction behaviors

Stimulus Control

When a behavior has been consistently reinforced in the presence of a certain stimulus, that stimulus will begin to affect the probability of the behavior SD –signals the availability of the reinforcement

Increases the probability that the behavior will occur under stimulus control – presence of a SD reliability

affects the probability of a behavior

Stimulus generalization

Generalization: the tendency for an operant response to be emitted in the presence of a stimulus similar to the SD

Generalization gradient

Stimulus Discrimination

Reinforcement of responding in the presence of one stimulus and not another stimulus Discriminative stimulus for extinction – a

stimulus that signals the absence of reinforcement

Peak shift effect- the peak of a generalization gradient following discrimination training will shift from the SD to a stimulus that is further removed from the SΔ

Multiple Schedules

Two or more independent schedules presented in sequence, each resulting in reinforcement and each having a distinctive SD

Differs from chain schedule? How? Different response for each SD

Behavioral contrast: a change in the rate of reinforcement on one component of a multiple schedule produces an opposite change in rate of response on another component. Negative contrast effect Positive contrast effect Anticipatory contrast

Fading & Errorless Discrimination

Discrimination training is an effective way to establish stimulus control Has it’s limits Prone to frustration and emotional behavior

Errorless discrimination training: gradual training procedure that minimizes the number of errors and reduces adverse effects of discrimination training

Errorless Discrimination Training

Two aspects:1. Discriminative stimulus for extinction (SΔ)

is introduced early in training, soon after the animal has learned what the SD is

2. SΔ is presented in weak form to begin with and then gradually strengthened

Fading: gradually altering the intensity of the stimulus

Stimulus Control : Additional Apps

Targeting

eliminating target behavior through putting a behavior “on cue”

Creating salient cues

Treating sleep-onset insomnia