Punishment

Definitions?

• Learning from the consequences that produce pain or discomfort

• The loss of reinforcers: This has survival value for the individual and for the species.

• Punishment teaches us not to repeat responses that cause us harm

• Any stimulus or event, when used contingently, decreases the probability of a response.

Nature of Punishment

• Punishment is defined neither by – the actions of the person delivering the

consequences– nor by the nature of those consequences.

• A decrease in the future frequency of the occurrence of the behavior must be observed before a consequence qualifies as punishment.

Definitions of Punishment

• Positive or Type I Punishment : – Presentation of a stimulus (or an increase in the intensity of an

already present stimulus) immediately following a behavior – results in a decrease in the frequency of the behavior.– Spanking, electric shock, etc.

• Negative or Type II Punishment: – termination of an already present stimulus (or a decrease in the

intensity of an already present stimulus) immediately following a behavior

– results in a decrease in the future frequency of the behavior.– Response cost, overcorrection

Discriminative Effects

• Stimulus condition in the presence of which a response has a lower probability of occurrence than it does in its absence

• Response-contingent punishment: – Delivery occurs in the presence of a stimulus cue– Punishment only occurs when emitting contingent response.

• Stimulus control is important:– If punishment occurs only in some stimulus conditions and not in others: the

suppressive effects of punishment will be most prevalent under those conditions

– Organism learns the setting conditions as to when punishment will occur– E.g.: Teacher has to see you misbehave

Punishment is also Known as Aversive Control

• Note that aversive events are associated with both:– positive punishment – negative reinforcement

• Term aversive control is often used to describe intervention involving either or both of these two principles.

Aversive but not contingent?

• Aversive stimuli can also affect operant behavior when given noncontingently– That is, a targeted behavior neither produces

nor prevents the punisher– when aversive stimuli occur independently of

responding.

• Most famous example is conditioned emotional response (CER)

Conditioned Emotional Response (CER)

• Basic set up:– Rat must lever press to obtain food. – Rat receives periodic pairings of tone with electric

shock. (tone signals the shock)– Rat eventually press lever at a lower rate when

tone is on than when it is off.

• Phenomenon is called conditioned suppression or conditioned emotional response (CER; Estes & Skinner, 1941).

Why are CER’s important?

• The “threat” of an upcoming aversive event can decrease responding– Even when noncontingent– Unpredictability produces GREAT CERs

• Because the aversive event is likely, organism “prepares” or “gets ready” for the event– Can be cued or uncued– Really gets in the way of ongoing responses

• E.g., in dog training: if dog is afraid of being punished– Rate of overall responding goes down– Animal is afraid of punisher, so doesn’t ‘risk’ behaving

Parameters of Punishment

• Is all we learned about positive reinforcement true, in mirror-image form, of punishment? – Yes and no.– Are some additional characteristics of punishment

• Any operant punishment situation is really a punishment plus reinforcement situation.– Just like any reinforcement situation =Sr + P– If get punished, don’t get the reinforcer.– If get the reinforcer, don’t get punished.

Punishment + Reinforcement?

• For punishment to suppress operant responding, responses must already be occurring with some frequency.

• For responses to occur, they must be producing reinforcement.

• So, effect of punishment reflects interaction of two contingencies--reinforcement and punishment.

• Jointly operate in most situations.

Punishment Effectiveness

• Punishing only reinforced response is often not an effective procedure.– Suppresses responses– Doesn’t provide a “replacement” response

• If you give organism an alternative, unpunished route to reinforcement, then effects of punishment are enhanced.

• Always shape an incompatible response!– A response that is the opposite of the inappropriate

response– E.g., punish getting out of seat but reinforce sitting in seat

Punishment Intensity:

• As intensity of punishing stimulus increases, degree of suppression increases.

• If very intense shock is used, then suppression may be virtually complete.

• Partially due to physiological effects; partially due to contingency effects

Role of past experience!

• Experience with the punisher is important– If never experienced shock, don’t know it hurts!– Punishment effects are relative: What has been prior

experience and how is the punisher COMPARED to previous punishers?

• Lots of research showing this:– Suppressive effect of intermediate shock intensity depends

on animal’s past experience with shock.

– If animal has experienced intensities going from mild to intermediate, then there will be little suppression.

– If animal has experienced intensities going from severe to intermediate, then there will be substantial suppression.

Immediate is Best!

• For punishment to be maximally effective, it must immediately follow operant response.

• As delay interval between response and punishment increases, amount of suppression decreases.

• Too many other behaviors can occur between R and P; contingency not as effective when initially using P

Probability of a punisher

• Initially: should be certain and follow each operant response.– Probability of punishment should be 1.0– When responses are punished intermittently,

effectiveness of punishment procedure is reduced.

• Can shape towards partial schedule of punishment

• Is this different than what observe with reinforcement? Think about it!

Recovery from Punishment: Extinction

• When punishment is discontinued, suppressive effects on responding ARE not permanent

• The rate of responding after punishment is discontinued will – not only recover – But briefly exceed level at which it was occurring prior

to punishment– Opposite of extinction burst– Is this really surprising?

Unconditioned Punishers

• Unconditioned punisher: stimulus whose presentation functions as punishment without having been paired with any other punishers.

– Innate– Biologically relevant– Still, all organisms not respond the same!

• Unconditioned punishers will suppress any behavior that precedes their onset.

• Again, is this similar to reinforcement?

How are Conditioned Punishers different?

• Conditioned punisher is a stimulus that functions as punishment as a result of a person’s conditioning history. – E.g., the word “no” is a conditioned stimulus– A child’s name can become a punisher!!!!

• Acquires capability to function as punisher through stimulus-stimulus pairing with one or more unconditioned or conditioned punishers.

Extinction of Conditioned Punishers

• If responses occur in absence of punisher, the response will return, potentially to pre-punishment levels

• If the conditioned punisher is repeatedly presented without the punisher with which it was initially paired, effectiveness as punishment will diminish until it is no longer a punisher.

Generalization and Discrimination

• Stimulus that has been paired with numerous forms of unconditioned and conditioned punishers becomes a generalized conditioned punisher.

• Stimulus that has been paired with only one specific conditioned or unconditioned punisher becomes a discriminated punisher.

Other factors influencing effectiveness of punishment:

• Schedule or frequency of punishment– Continuous punishment schedules knock down behavior more

quickly– Partial punishment schedules keep behavior suppressed more

effectively

• Availability of reinforcement for the target behavior– Must eliminate inadvertent sources of reinforcement for your

behavior targeted for punishment– Teacher may punish, but the other kids may keep reinforcing “class

clown” behavior

• Availability of reinforcement for an alternative behavior.– Punishment more effective if reinforce the opposite behavior– Again, must give organism alternative path to the reinforcer that was

maintaining the unwanted behavior

Is time out a punisher?

• Yes, by definition it is a negative punisher– Losing the opportunity to get reinforcement from

many other sources– Again, to be effective, must really isolate so can’t

get reinforced.

• Time out is not isolation– Time out is brief, focused and contingent– Isolation is of long duration, often noncontingent,

and often not effective.

Rules for Using Time-Out

• 1 minute per year of age– Not really effective for children under 6-9 mos– For really little ones, VERY brief withdrawal of

attention

• Must be quiet to get the timer to start

• Cannot use for dangerous, disruptive or self-stimulatory behavior

• Must really be “time out” from other rewards

Negative Punishment

• Response cost: your response costs you something or some behavior

• OVERCORRECTION: two parts– Restitution: reinstatement of environment

(clean up)– Positive practice: practice better response for

situation– Can also use satiation/habituation

Guidelines for using positive punishment

• Behavior must be (immediately) dangerous to person or others

• Rate of responding is so high that there is NO chance to interrupt and reinforce “good” behavior

• Must have tried other alternatives

• An example: http://www.youtube.com/watch?v=13UcT1FVVts

Examples:

• Severe self injurious behavior (SIB)

• Highly aggressive behavior to others

• Behavior which creates in immediate danger for self or others– Running into the street– Pulling a hot pan off the stove