Disequilibrium Approaches

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Disequilibrium Approaches

A newer model!

Goal of behavior analysis/operant conditioning

• Clarify control of human behavior by reinforcement contingencies

– many techniques have been developed

– used in wide variety of settings

• Problem: specifying ahead of time what works:

– no a priori way of determining what will be a reinforcer

– makes for problems in applied settings

– even lab research affected by this

• what usually do: reinforcer assessments

– time consuming

– not very accurate

Successful approach to a priori assessment should satisfy 3 practical requirements

Identification of Rs circumstances should involve:

• a small number of simple, nonintrusive procedures

– must be widely applicable

– require no special apparatus

– no novel or disruptive stimuli to be introduced

• must be accurate and complete

• result should be adaptable to variety of situations , rather than limited to small number of stimuli, responses or settings

Transituational Solution: conceptual Analysis

• Meehl, 1950: Transituationality of Reinforcement

– simplest method for figuring out what works: use what circumstances have worked in the past

– if works in one setting, should work in others

• Three important assumptions about reinforcing stimuli and their "setting conditions"

– reinforcers and punishers form unique, independent sets of transituationally effective stimuli

– essential function of the contingency = produce temporally proximate pairings between response and reinforcer

– deprivation schedule specifying long-term denial of access to reinforcer = critical setting condition

Transituational Solution: conceptual Analysis

• Problem:

– none of these holds up to data

– The assumptions are incorrect!

• reinforcers and punishers are not mutually exclusive nor are they transituational

• eg. Premack: drinking and wheel running could reinforcer each other

• applied settings see this all the time

• temporal contiguity not sufficient to produce reinforcement:

• Premack (1965): pairing wheel running w/drinking had no effect in absence of contingency schedule

• appear that contingency is key, not time

• long term deprivation not necessary nor sufficient: short term deprivation works

Application problems w/this approach:

• STILL is most often used technique

• Assessment techniques are intrusive

• Often NOT effective: reinforcers change over time

– Does not account for satiation effects, etc.

– Not account for different situations

– In applied world, do a reinforcer assessment once and assume it stays!

• Lacks flexibility, accuracy

• Ethical questions when using food, certain punishments

Premack's Probability Differential

Hypothesis: (Grandma’s Law)

• Premack (1959; 1965): distinct improvement over transituational view

– schedule in which a higher probability response is contingent upon a lower probability response will result in reinforcement

– if you eat your peas (low prob) then you can have chocolate pudding (high prob)

• important change in concept of reinforcement in several ways:

– reinforcement is related to access to a response

– probability of response determined by probability (duration) of that response in FREE BASELINE

• shows that transituational situation is special case of probabilitydifferential:

– highest probability response contingent upon a lower probability response

– as long as is highest probability- should be transituational

Premack's Probability Differential

Hypothesis: (Grandma’s Law)

• Some problems, however:

– incomplete and unclear about several things:

– fails to specify conceptual rules for setting values of contingency schedule:- pair 1:1, 5:1 or what?

• Unclear about role of reduction in contingent responding relative to baseline that typically accompanies an increase in instrumental responding

• Unclear about role of long-term deprivation

Application

• Probably most widely used behavioral technique

• Popularity due to several desirable characteristics:

– procedures for identification are clear, relatively non-disruptive

– more accurate than transituational method

– allows for far wider choices of Sr's and P's

• Problems even in applied arena:

– duration of discrete response hard to measure

– duration not always a good measure

– problem in that must always use higher probability responses as reinforcers

– time consuming to measure baselines

Response Deprivation and

Disequilibrium Approach

• Assumption: reinforcement results from adaptation of motivational processes underlying free baseline responding to the performance constraints imposed by a contingency schedule

• What's that?

– are constraining behavior that would naturally occur in free baseline to a set contingency schedule

– only allowing free baseline behavior to occur at certain levels, rates, times

– restrict via a contingency schedule

• really looking at molar equilibrium theory:

– free baseline = equilibrium state

– disrupt this equilibrium state via a contingency schedule

– assumes assessment of free-baseline of instrumental and contingent responding before imposition of contingency schedule

Response Deprivation and

Disequilibrium Approach

• does NOT view baseline as stable hierarchy of reinforcement value:

– estimate of relative motivation underlying different responses

– that is- can change from situation to situation

– Idea that just must disrupt baseline ratio and you create behavioral effects

• by imposing different contingencies- can create reinforcement and punishment conditions:

– response deficit: reinforcement

– response excess: punishment

Definitions

• I = instrumental response:

– The response you have to do to get the “reinforcer”

– Putting dishes in the dishwasher

• C = contingent response

– The response that serves as the reinforcer

– Watching TV

• Oi = amount of instrumental response that you will do with NO contingency (free baseline)

– If no contingency, how often would you freely load the dishwasher?

• Oc = amount of contingent response that you will do with NO contingency (free baseline)

– If no contingency, how often would you freely watch TV

Response deficits

• Response deficit: I/C >O i

/O c

– If individual maintains instrumental responding at baseline level, would engage in less of baseline level of contingent responding

– thus: if I continue to eat my baseline level of peas, I would engage in less chocolate pudding eating (than baseline)

– I/C = 1/25

• 2 peas; 50 spoonful chocolate pudding

– Oi/Oc: 1/100

– 1 pea; 100 cc’s of chocolate pudding

– Thus: 1/25 > 1/100

Response satiation

• Response excess: I/C < O i

/O c

– Is the individual maintains instrumental responding at baseline level, would engage in too much of baseline level of contingent responding

– if I hit my sister at baseline levels, I would engage in/receive more spankings than I engaged in/received during baseline

– I/C: 1/1

• 1 hit; 1 spanking =

– O i

/O c:

1000/1

• 1000 hits; 1 spankings

– Thus: 1/1 < 1000/1

Why an improvement?

• improvement for several reasons:

– specifies rules for setting terms of schedule:

– I/C > Oi/Oc for reinforcement effects

– I/C < Oi/Oc for punishment effects

• I = instrumental response

• C = contingent response

• Oi = baseline rate of instrumental response

• Oc = baseline rate of contingent response

• no limitations on units for measuring baseline behaviors, as long as keep same in contingency setting and ratio

• sets NO restrictions on what can be a reinforcer or a punisher

• note: lower probability response can reinforcer higher probability response, as long as setting conditions are met

• shows that long term denial is NOT necessary:

– Critical: allows for deprivation or disequilibrium within a session

– long term denial is special case of this

Applications

• Several desireable reasons for using:

– procedures specific

– relatively non-disruptive

– more accurate

– allows incredible flexibility- no set reinforcers or punishers

• Examples: Konarski (1980):

– grade school kids

– free baseline of coloring or working simple arithmetic problems

• Konarski (1985): EMH classroom

– retarded children

– working arithmetic problems and writing

• incidental teaching

– behavior contracting: Dougher study (1983)

– good behavior game

– overcorrection: punishment technique

Incidental teaching and the Minimum bliss point model

Farmer-Dougan, 1998

• Bitonic relationship between rate of reinforcement imposed by a schedule and strength of reinforcement effect

– Response rate first increase then decrease as reinforcer rate increases

– When schedule provides very high rate of reinforcement

(disrupts disequilibrium only slightly) – little change in instrumental responding

– When schedule provides very low rate of reinforcement

(disrupts disequilibrium to high degree), little net reinforcement effect

• Thus, extreme rates of reinforcement should be less effective than moderate rates

Can mathematically predict reinforcement effects!

• Simple FR schedule: according to minimum distance models, R rate that produced by ratio schedule is equal to:

– R1 = predicted rate of response

– Oi is rate of unconstrained instrumental response

– Oc is rate of unconstrained contingent response

– K is number of units reinforcement/response (inverse of FR requirement)

Predict an Inverted U-shaped function

Incidental teaching

• Accurately IDs reinforcers and increases generalization and maintenance via use of naturalistic teaching

• Involves capturing a teaching moment (Hart and Risley, 1980)

– Subject initiates (verbally/physically) toward an item or activity

– Teacher immediately imposes contingency such that access to the item/activity is blocked until the contingent response is emitted

– Immediate assessment of baseline and immediate imposition of momentary disequilibrium

• Question: how often to disrupt?

– Minimum bliss models suggest that moderate amounts should be better than high interruption or very low interruption

Method

• 4 head start preschoolers

• Worked 1:1 in workroom at Head

Start

• Set of toy items for each child, and set of 26 flash cards containing letters

A to Z

• Task: ID letter expressively to gain access to toy

• Manipulated rate of disruption:

– Baseline (0)

– 25%

– 50%

– 75%

– 100%

Results!

• Little academic behavior when did not disrupt (

– surprisingly, there was some

– but differed by child

– Shows differences in baseline rates

• Too much disruption = no academic responding!

• Moderate levels worked best!!

Limitations on/Extensions of

Disequilibrium approach

• not completely accurate

– how to measure baseline for individual subjects

– time consuming nature of measuring baseline

– only takes into account 2 behaviors (I and C), while many more behaviors occur in any contingency setting

• Question of time frames: do baselines change w/time?

– Does constraining baseline affect or reset baseline?

Conclusions

• Strong need to predict reinforcement ahead of time

– if can't- not very usable concept

– early theories did not do this very well

• Reinforcers and punishers aren't things:

– no magic wand

– reinforcement/punishment effects depend upon extent to which contingency schedule constrains the free distribution of responding

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