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Published byMoris Roberts Modified over 9 years ago
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Disequilibrium Approaches A newer model!
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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
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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
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Transituational Solution: conceptual Analysis Meehl, 1950 – 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
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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
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Application problems w/this approach: STILL is most often used technique Assessment techniques are intrusive Not very effective: reinforcers seem to change Does not account for satiation effects, etc. Lacks flexibility, accuracy Ethical questions when using food, certain punishments
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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 probability- differential: – highest probability response contingent upon a lower probability response – as long as is highest probability- should be transituational
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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
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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
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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
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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
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Response deficits and satiation 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) 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
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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
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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
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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
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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)
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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
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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%
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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!!
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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?
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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 contingencyschedule constrains the free distribution of responding
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