4-Reinforcement arrangements in applied to settings ll: detriments of reinforcer efficacy Flashcards
Zhou, Iwata,
• examined Stability of preferences over TIME in 22 adults with IDD.
• Conducted PS preference assessments at point
1.
• repeated the PS preference assessments for leisure items at intervals ranging between 12 and 20 months apart
• examined Rank Order correlations between the first and second assessments.
Mean rank-order correlation = 0.11 across participants
***GREATER STABILITY for most participants when only the top 5 stimuli are considered
• Suggests highest preferences may be more STABLE
• Corresponds with informants ability to offer
accurate opinions about reinforcers
Stability of preferences
Diagnosis: Do individuals with ASD display more stable preferences than individuals without similar diagnoses?
Stimulus type: Are food preferences more or less stable than non-food preferences?
Ciccone,: Examined rank-order correlation Coefficients for food only
Zhou: Leisure items only
Castillo,
Proportion and mean correlation for 1st vs. 2nd greater for edibles for all analyses
Findings: some validity that food preferences are more stable than non-food preferences
However, number of differences between the two studies: differing preference assessment, N, and interval between assessments
What shall we make of these
differences?
Why might food preferences be more
stable?
• Local and temporally extended satiation effects
for leisure items?
Potentially, categories showing greater
stability may require less frequent assessment?
• However, there are dangers inherent in
adopting this stance…
Shifts in Preference and Stimulus Value
• Local and temporally extended satiation effects for leisure items?
Potentially, categories showing greater stability may require less frequent assessment?
• However, there are dangers inherent in adopting this stance…
DeLeon
changes in preference associated with corresponding changes in the UTILITY of reinforcers?
Analysis
Conducted one lengthy Paired stimulus preference assessment before the study
Conducted brief MSWO PA before daily training sessions
•Utility of Frequent Assessment in Acquisition
-Sometimes helps; sometimes does not. Determining factor:
•Variable preferences!
Why might food preferences be more stable?
Zhou, Iwata, Goff, & Shore (2001):
Examined stability of preferences over time
22 adults with IDD
Conducted PS preference assessments at point 1
Repeated the PS preference assessments for leisure items at intervals ranging between 12 and 20 months apart
Examined rank-order correlations between the
first and second assessments
**Greater stability for most participants when only the top 5 stimuli are considered:
• Suggests highest preferences may be more stable
• Corresponds with informants ability to offer accurate opinions about reinforcers
Shifts in Preference and Stimulus
Value
Castillo, DeLeon, & Frank-Crawford (in preparation)
3 preference assessments, 12 items
Edible (N = 31) or nonedible (N = 38)
Does stability at 1st vs. 2nd predict 2nd vs. 3rd
Analyses:
• 3 out of 4: Did at least 3 of the top 4 remain
among the top 4?
• Top-ranked: Did stimulus ranked #1 stay #1?
• Correlation: Was the correlation of all ranked
0.7?
***Proportion and mean correlation for 1st vs. 2nd greater for edibles for all analyses
Shifts in Preference and Stimulus
Value
What shall we make of these differences?
Why might food preferences be more stable?
• Local and temporally extended satiation effects
for leisure items?
Potentially, categories showing greater stability may require less frequent assessment?
• However, there are dangers inherent in
adopting this stance…
Shifts in Preference and Stimulus
Value
DeLeon et al. (2001):
Are changes in preference associated with corresponding changes in the utility of reinforcers?
Analysis
Conducted one lengthy PS PA before
the study
Conducted brief MSWO PA before daily
training sessionsShifts in Preference and Stimulus
Value
How STABLE are preferences and reinforcer efficacy over time?
Are changes in preference associated with corresponding changes in the utility of reinforcers?
Shifts in Preference and Stimulus Value
Zhou et al. (2001):
Mean rank-order correlation = 0.11 across participants
However, greater stability for most participants when only the top 5 stimuli are considered:
• Suggests highest preferences may be more stable
• Corresponds with informants ability to offer accurate opinions about reinforcers
Xxxxxxx in Preference and Stimulus
Value
Does stability differ according to:
Diagnosis (ASD vs. non-ASD)?
Stimulus type (food vs. non-food)?
XxxxxxShifts in Preference and Stimulus
Value
Zhou, Iwata:
STABILITY of preferences over time
•22 adults with IDD
•Conducted PS preference assessments at point 1
- Repeated the PS preference assessments for leisure items at intervals ranging between 12 and 20 months apart
- Examined RANK-order correlations between the first and second assessments
CONCLUSIONS:
- Greater STABILITY for most participants when only the top 5 stimuli are considered:
- Suggests highest preferences may be more stable
•Corresponds with informants ability to offer accurate opinions about reinforcers
Stability:
Shifts in Preference and Stimulus
Value
- MOMENTARY Capacity to support responses that produce it
2. UTILITY in producing LONG- term Behavior change
Effectiveness of a Reinforcer
- Pairing less preferred activity with established reinforcers through contingent delivery
- Pairing less preferred activity with established reinforcers through non contingent delivery
Hanley, Iwata: Examined choices between activities in a CONCURRENT Chain.
•First link determined subsequent activity and then differing arrangement/schedules in the subsequent activity.
•They measured a proportion of selections as a function of reinforcement delivered for engagement – not choosing – in the less preferred activity. Does this impact choices?’s
Edible reinforcement and NCR music while doing dishes
Can we make something preferred when it was not already By
Hanley: Shifting activity preferences
Hanley, Iwata :
• Selected one high preferred and one low preferred activity, measured relative Response Allocation.
In conditioning procedure, established reinforcers were delivered on FT schedules during access to low preferred.
No reinforcement during access to high preferred.
Each arranged for three, five minute sessions, followed by tests Sessions (no consequence for either activity)
CONCLUSIONS:
- Enhancing an activity with SUPPLEMENTAL CONTINGENT reinforcement can SHIFT choices towards that activity
- Non-contingent PAIRING of an activity with ESTABLISHED preferred stimuli can SHIFT choices toward that ACTIVITY
Effects seem to be TRANSIENT (do not persist after discontinuation of the Pairing procedures)
Determinants of Stimulus Value
Continuing research- Hanley
Examined affects of SATIATION and CONDITIONING on Preference RANKS.
Conducted INITIAL preference assessment then a SATIATION condition for HIGH preference stimulus
Free access for 2 to 3 hours per day, and conditioning for a low preference stimuli, pairing the stimulus with continuous attention and continue with availability I prefer edibles, five, one minute trials per day. Exposure for the control stimuli was 51 minute child per day.
Hanley Iwata Roscoe
DELAY to reinforcement: widely studied in context of
- treating problem behavior
- Research on Temporal discounting
- Self control.
Are conditioned reinforcers less susceptible to adverse affects of delay?
Determinants of Stimulus Value:
Delay
Leon Examined the effects of Delayed reinforcement with primary and conditioned reinforcer.
Three Conditions:
1. Baseline – no Reinforcement
2. FR 1 no delay (responses produced a reinforcer immediately)
3. FR1 increasing delay
(responses produced a reinforcer following 1 of 5 delays)
Assessed delayed of food, delayed tokens, and immediate tokens with a delayed exchange
CONCLUSIONS:
• delayed FOOD produced the greatest Persistence
• Delayed TOKENS produced most RAPID decreases in responding,
- Token delivery with a delayed EXCHANGE opportunity equaled or exceeded Effects of delayed food.
Conditioned reinforcers less susceptible to adverse affects of delay.. depends on when they are OWNED and EXCHANGED
Determinants of Stimulus Value:
Delay
Effects relative response allocation
Matching law (ML): Organisms will distribute behavior among concurrently available
alternatives in same proportion that reinforcers
distributed among those alternatives
In humans, the ML obtains for
Problem behavior
Academic responding
Communicative behavior
Leon, Deleon: Rate of reinforcement:
Determinants of Stimulus Value
higher preference = better ______
Studies have compared responding for
reinforcers of varying preference
•However, as noted earlier, HP and LP stimuli sometimes support SIMILAR RATES of responding
Research on amount of work completed for stimuli of varying preference assessed via Progressive Ratio schedules
Higher preference, better quality reinforcers:
- More Potent reinforcers
Quality of reinforcement
Determinants of Stimulus Value:
Leon, Deleon
Can vary according to:
Quantity
Intensity
Duration
Mixed results examining effects of ____
Some suggest a positive relation between magnitude and responding
Other suggest no relation
Function of schedule of reinforcement?
Magnitude of reinforcement
Trosclair
Preference assessment: Concurrent operant arrangement used to assess the participants’ preferences for two different reinforcer magnitudes (i.e., small vs. large or medium vs. large) and no reinforcement
Progressive Ratio analysis conducted to assess reinforcer EFFICACY
may play an important role when THINNING schedules of reinforcement
Magnitude
effects of different reinforcer magnitudes on preference and reinforcer efficacy
An environmental event, operation, or
stimulus condition that serves the following 2 functions
- Reinforcer establishing function:
Momentary alters the reinforcing effectiveness of other events - Evocative function: Momentarily alters the frequency of occurrence of the type of behaviors that produces those other events as a consequence
Motivating Operation (EO):
Determinants of Stimulus Value:
Motivating Operations
Momentarily increases the reinforcing
effectiveness of that stimulus.
Momentarily increases the frequency of behavior that produce the stimulus as a consequence
Stimulus deprivation
Determinants of Stimulus Value:
Motivating Operations
Momentarily decreases the reinforcing
effectiveness of the stimulus
Momentarily decreases the frequency of behaviors that have produced the stimulus as a consequence
Stimulus satiation
Gottschalk):
Deprivation and satiation effects with food on preference assessment OUTCOMES:
• Control: Regulated (premeasured) access for
24 hr before assessment
- Deprivation: 48 hour deprivation for one stimulus at a time; regulated access for others
- Satiation: 10 min free access before assessment; regulated access for other
Paired-stimulus preference assessment
following manipulations
***SATIATION can influence preference RANK
Determinants of Stimulus Value:
Motivating Operations
Can influence preference RANK
CAN similarly influence PERFORMANCE
-Depends upon the specific OPERATION and the person
Satiation
Determinants of Stimulus Value:
Motivating Operations
Zhou, Iwata):
Deprivation and satiation for food reinforcers under less contrived arrangements
Deprivation: 30-min before lunch
Satiation: 30-min after lunch
No additional exposure, unlike Vollmer &
Iwata (1992)
Determinants of Stimulus Value:
Motivating Operations
Conclusions on motivating operations:
Zao, Vollmer
• Can influence preference assessment results
•May influence reinforcer VALUE but not
necessarily under NATURALISTIC conditions
• More interesting examples may not involve deprivation or satiation, but CONDITIONED establishing operations
-Transitive CEO manipulated to enhance motivation for mands in response chains
Are there different “kinds” of satiation?
Are the sorts of changes in deprivation/satiation correlated with normal life enough to shift response
patterns?
Vollmer Examined rates of SIMPLE responses under conditions of deprivation satiation
Deprivation/Satiation
Determinants of Stimulus Value:
Motivating Operations
Can the effectiveness of a reinforcer be
influenced by the nature of other, qualitatively different reinforcers in the environment?
Behavioral economics:
-Imports principles of microeconomics to the
study of OPERANT behavior
Determinants of stimulus value: behavioral economics
Investigation of choice under conditions
of asymmetrical reinforcers
Investigation of consumption under various conditions of constraint
Once the parallels are drawn and validated, opens the door to relations heretofore only considered by
economists
Why behavioral economics in IDD?
Commodities:
Econ: Goods and services
B. Econ: Reinforcers
Unit Price:
Econ: $ paid per unit of commodity
B. Econ: Number of responses “paid” per
unit of reinforcer
Consumption:
Econ: Total quantity of a commodity
consumed, typically at the population level
B. Econ: Total amount of a reinforcer
obtained per unit time, typically at the
individual level
Behavioral Economics – Some
Terms
Population Demand Curve
See Co instructor material
Individual Demand Curve
Co instructions
Sensitivity to price. That is the Extent to which changes in unit price influence consumption of the commodity
Changes in price produce larger than proportional changes in consumption E. G., 1% increase in price produces greater than 1% decrease in consumption
Stimuli with equivalent initial consumption (Under low-cost conditions), May have very different demand profiles
Elasticity of Demand
Changes in price produce less than proportional changes in consumption. E.g.., One percent increase in price produces less than 1% decrease in consumption
Inelasticity
Influences:
• Constraints on income regarding luxury goods versus necessary goods.
-Demand for a luxury goods is made elastic
-Eg, Demand for gasoline at four dollars a gallon is relatively any elastic;
-Demand for a Coca-Cola at four dollars a can would not be
- Open versus closed economics
- Closed economy:
- Greater defense of consumption
Nature of available alternatives.
Influences elasticity of demand
Consumption of a reinforcer is NOT dependent on responding within earning context. (supplemental access to a reinforcer is provided outside of the earning context)
Open economy:
Consumption of a reinforcer is entirely Dependent on responding within earning context – no supplemental access
Closed economy:
less elastic curves – under closed economics than open economics
Greater defense of consumption
Demand is more elastic when SUBSTITUTABLE reinforcers are concurrently available
Substitutable reinforcers: Reinforcers that
share important functional properties
-E.g., two food items
Nature of available alternatives
What Influences Elasticity of
Demand?
How is Reinforcer affectedness influenced by the nature of other qualitatively different reinforcers in the environment?
Does the finding hold in persons with IDD?
Demand curves very with Similarity of alternatives.
Consumption declines more rapidly as :
- Price Increases when the alternative is functionally similar. - As delay increases When alternative is functionally similar
Elasticity of Demand
Clinical implications of:
Consumption declining more rapidly as :
- Price Increases when the alternative is functionally similar.
- As delay increases When alternative is functionally similar
Typical course of intervention for a severe problem behavior in IDD is:
1. Assessment to identify the Functional reinforcer
2. Differential reinforcement
– Provide functional reinforcer for alternative behavior
- Extinction relation between problem behavior and functional reinforcer is disrupted ,
- Schedule thinning for practicality
Provide DISSIMILAR reinforcer
Elasticity of demand- Clinical Implications
does the amount of work the person has to complete to earn a reinforcer influence the subsequent effectiveness of that reinforcer
Determinants of stimulus value: contingency
Contingency and Stimulus Value
“..such are the Tempers and dispossissions of
Seamen in general that whatever you give
them out of the common way, altho it be ever
so much for their good yet it will not go down
with them and you will hear nothing but
murmurrings gainest the man that first invented
it; but the Moment they see their superiors set
a Value upon it, it becomes the finest stuff in
the World and the inventor an honest fellow.”
- Captain James Cook , April, 1769
“
The harder the conflict, the more
glorious the triumph. What we obtain
too cheap, we esteem too lightly.“
-Thomas Paine, The Crisis, 1776
Ugh!
Clement et al. (2000): Assessed effects of past effort on the current value of SDassociated with identical reinforcers
What about the effects of past effort on
the current value the reinforcer itself?
Or on the value of different reinforcers?
Pre-test
-Stimulus preference assessment – choose
middle 4
-Progressive-ratio assessment
Manipulations (4 weeks) Constant FR1 Escalating FR Time-based, noncontingent delivery ie. free stuff) Restricted
Post-Test
Repeat pre-tests
Measure difference scores
DeLeon et al. (2011):
Free reinforcers lose value more rapidly than earned reinforcers
Are interventions that involve contingent reinforcers more durable than interventions that involve noncontingent reinforcers?
The loss of earned reinforcers are more potent than the loss of free reinforcers?
Contingency and Stimulus Value
Variable effects:
• Contingent stimuli do not always increase in value and greater effort is not related to greater increase in value
Consistent effects:
•. Noncontingent delivery may devalue stimuli
more rapidly
• Did contingency at least help to preserve
value against what might be a natural decline?
• Is the decrement sufficient to impact clinical intervention?
Contingency and Stimulus Value
“…reinforcers need not be consumed
following each completion of a schedule
requirement but rather can be accumulated, then collected and consumed later.”
McFarland & Lattal (2001) JEAB
We want kids to accumulate reinforcers
Does not interrupt ongoing behavior
Requires fewer teacher resources
But…the inherent delay
What promotes accumulation?
Consumption cost (Yankelevitz et al., 2008)
Interest for savings?
The nature of the reinforcer? Continuity?
Reinforcer Accumulation
Much of our knowledge of reinforcer effectiveness is built on providing brief access to reinforcers following small numbers of responses Is this really what kids want?
Continuity and Stimulus Value
Procedures that interrupt continuity
might alter the quality of the reinforcer,
thus discounting its effectiveness
(Hackenberg & Pietras, 2000)
The effectiveness of some reinforcers (e.g., video) might partly depend on uninterrupted access
Is the individual willing to “pay” to preserve continuity?
Continuity
DeLeon,
Does continuity matter?
Experiment 1: Do delayed, accumulated
reinforcers (mediated by tokens) support
rates of responding equivalent to distributed reinforcement?
Experiment 2: Do children with IDD prefer
to accumulate access to activities and
food?
Continuity and Stimulus Value
Experiment 1 Efficacy
ABAB Reinforcer Assessment
-A = No reinforcement BL
-B = Multi-element comparison of
Distributed reinforcement: Delivery of a brief
period of access each time a small response
requirement is met
Accumulated reinforcement: Delivery of all
reinforcement at the same time following the
completion of a larger response requirement
-Measure: Rates of simple free-operant
responses
Highest mean rates of responding observed
in accumulated reinforcement condition
-Added value in arranging accumulated
reinforcement?
-Handling Costs”?
Continuity and Stimulus Value:
Is demand for delayed, accumulated
access more or less elastic as an equal
amount of immediate, but distributed
access?
Is demand for delayed, accumulated access more or less elastic as an equal amount of immediate, but distributed access?
Conclusions about Accumulation
Accumulated access, mediated through
tokens…
-Supports faster work
-Supports greater overall quantity of work
-Is preferred by learners
Why do we care? “Dissimilar” reinforcers
may produce more “durable” TX when
(1)Problem behavior is reinforced,
2)Reinforcement of appropriate behavior thinned
Tokens exchanged for accumulated activities:
1) Have same desirable qualities as edibles
(2) May produce similar therapeutic effects
(3) Lack “undesirable qualities
Continuity and Stimulus Value:
Amount of Work
Accumulated access, mediated through tokens…
Supports faster work
Supports greater overall quantity of Work
Is preferred by learners
Is it really about continuity
Conclusions about Accumulation
Individuals may prefer continuity with work as well!
Conclusions about Accumulation
Accumulated access, mediated through tokens…
-Supports faster work
-Supports greater overall quantity of work
- Is preferred by learners
The real utility of tokens are as generalized-conditioned reinforcers…
Reinforcer Accumulation
Continuity and Stimulus Value
Can varying reinforcers or providing choice-of reinforcers produce beneficial effects?
Several methods for incorporating different
reinforcers
-Frequent preference assessment (e.g.,
DeLeon et al., 2001)
-Stimulus variation
-Pre-session selection
-Post-response reinforcer choice
Determinants of Stimulus Value:
Variation and Choice
Arranges for rotation of different reinforcers following responding
Found to increase response rate and
decrease interresponse time
May be preferred even if the varied reinforcers are of lesser preference but still moderately preferred
Stimulus variation appears to have some effect but only in so far as the stimuli that are being presented are moderately to highly preferred
Effect of stimulus variation seems to
be idiosyncratic across individuals
Moderately to highly preferred stimuli seem to have some effect on response rate and IRT
Stimulus variation:
Pre-session selection
Ask the learner which reinforcer they
would like to earn in the following
instructional session
Within-session (post-response) choice
-Permit the learner to choose from a
small array of reinforcers each time the
schedule requirement is me
Determinants of Stimulus Value:
Choice
• Yoking studies suggest no effects of
choice
• The problem with yoking procedures
Although they approximate a method of control for momentary fluctuations in preference,
They are not perfect because preferences may change across brief time spans or as a function of exposure in preceding sessions
How, then, to perfectly isolate the effects of choice?
Determinants of Stimulus Value: Choice
Smith: No effect of choice in single operant
Tiger et al. (2006): Preference for choice in concurrent choice
Conclusions:
Choice may be preferable but not always
beneficial
Is it a case of a slight effect that would show
up under very sensitive arrangements, but
not insensitive arrangements?
Determinants of Stimulus Value:
Choice
Choice
Geckeler, Libby,
Examined response rates during choice and no-choice conditions on FR schedules (FR 20 to FR 30) Evaluated under single-operant schedule Evaluated under concurrent schedule Two identical responses available Could work on either one
Determinants of Stimulus Value:
Choice
Determinants of Stimulus Value: Choice
Things we know less about when considering choice of reinforcement
Are there situations in which choice may be
aversive?
Are choice effects sufficient to override other
inequities in concurrent reinforcement arrangements?
Choice effects in single-operant schedules when preference levels are unknown?
Choice under PR schedules?
Does it matter in acquisition?
Things we know less about when considering choice of reinforcement
In formal terms, of course, this never
happens
Reinforcement is defined by its effect on the response upon which it is made contingent – it increases responding
So, assuming the contingency was executed with fidelity, no change in responding may result from
Contrived external contingencies where
contingencies were not needed (e.g.,
detrimental effects of extrinsic
reinforcement on intrinsic motivation)
Procedural “mismatches” between the
response and its outcome
What if “Reinforcement” Doesn’t
Work?
The stimulus used was not a reinforcer
It was perhaps chosen arbitrarily or based upon conventional wisdom, but never directly
evaluated for its reinforcing efficacy
E.g., this may happen often with social praise
Preference and/or reinforcer assessment should be used to systematically determine or at least to estimate the likely effectiveness of the stimulus as a reinforcer before it is incorporated into the relevant context
The stimulus was not a reinforcer under the specific conditions in which it was arranged
The item delivered contingent upon the target response was insufficiently effective relative to that response
It may have been tested for reinforcer
effectiveness under separate (perhaps less stringent) conditions and found effective, but efficacy did not extend to current conditions
Important to test reinforcer effects under conditions that approximate the conditions of their use in the relevant context
Procedural Mismatches
The stimulus used was no longer a reinforcer under these conditions
It was once a reinforcer under these conditions, but effectiveness has since been altered by some other event
-E.g., satiation, developmental changes
The use of ineffective stimuli in the relevant context can be avoided by repeated preference assessments across time
A response-reinforcer contingency was arranged but was not contacted
E.g., the requisite performance was too difficult or too effortful to meet reinforcement requirements, so it rarely occurred
Smaller, less stringent steps may be needed to shape and bring the behavior into contact with the
contingency
The stimulus followed the wrong response
E.g., trying to increase on-task behavior by arranging contingencies for sitting at one’s desk does not mean one will actually do the work
The reinforcer must depend directly on the behavior of interest rather than on other behavior that is incidentally correlated with it
Procedural Mismatches
Assuming that the contingency was executed with fidelity, a decrease in responding may result from
Overjustification
Punishment: Time-out from preferred activity
Discriminative properties of reinforcers:
-Reinforcer evokes incompatible behavior
Responding?
Frank-Crawford et al. (2012):
Delivery of the food disrupted engagement not because it decreased motivation to engage with the stimulus, but rather because food functioned as a discriminative stimulus in the presence of which requests for edible stimuli had historically been reinforced
What if “Reinforcement” Decreases Responding?
Not STATIC
Preferences
Determinants of preferences and reinforcer Effectiveness
The requirements for reinforcement are increased systematically, usually after each reinforcer.
Under Progressive Ratio (PR) schedules
Can influence preference Rank
Satiation
MO’s Effectiveness on reinforcer value
DISSIMILAR reinforcers are more Durable when:
- Problem behavior continues to be reinforced
- Reinforcement of appropriate behavior is PROGRESSIVELY Thinned
Reinforcer value – IDD
Free reinforcers lose value more rapidly than earned reinforcers
DeLeon et al. (2011):
(economics) Demand curves vary with similarity of alternatives
Consumption declined more rapidly as price increases when alternative is functionally similar.
Findings in persons with IDD
Elasticity
Vary with similarity of alternatives
Consumption declines more rapidly as delay increases when alternative is functionally similar
Demand curves
IDD– elasticity of demand
- Available alternatives
2. Substitutable reinforcers
Influences elasticity of demand
Dissimilar reinforcers are more Durable when:
- Problem behavior continues to be reinforced
- Reinforcement of appropriate behavior is progressively THINNED
(Clinical implications – elasticity)
Can WEAKEN the effectiveness of behavioral arrangements
Decrease VALUE of a reinforcer
Delays to reinforcement:
Discounted more STEEPLY Then conditioned reinforcers.
Primary, directly CONSUMABLE Reinforcers
Less susceptible to adverse affects of delay.. depends on when they are OWNED and EXCHANGED
Conditioned reinforcers
Difficult to quantify it because Of it’s dynamic:
- CHANGES as a function of a number
• Can have value Enhancing Effects (mere exposure) through:
-Learning how to extract reinforcement?
-Explains displacement of leisure items by food?
-Reinforced engagement?
- (Long-term satiation)
Reinforcer effectiveness
Food preferences more stable than non-food preferences
However, number of differences between the two studies: differing preference assessment, N, and interval between assessments
Stimulus Preference Value
Associated with corresponding changes in UTILITY of reinforcers
Utility of Frequent Assessment in Acquisition
-Sometimes helps; sometimes does not. Determining factor:
•Variable preferences!
Changes in food preferences
substitutable reinforcers are …
Reinforcers that are similar
Can also mean changes in the EFFECTIVENESS of stimuli,
Time not necessarily the relevant independent variable
Changes in preferences
Demand is more elastic when
substitutable reinforcers are concurrently available
