1. Applications of the Matching Law

2. Behavioral Contrast
Behavioral contrast: often found "side effect“: original study: Reynolds, 1961
pigeons on CONC schedules of reinforcement with equal schedules at first
then, extinguish reinforcement on one alternative
got HUGE change in responding for non-EXT alternative
why? Behavioral contrast- changed value of schedule
also called the Pullman effect!!!!

3. Behavioral Contrast Helps explain "side effects" of reinforcement:
e.g.: EXT boy talking to teacher during class, but then kid talks more to peers
Why?
P1/P2=R1/R /100 = 100/100
But then one option goes to EXT
P1/P2=R1/R /100 = 100/0?

5. Behavioral Contrast
Example: boy talking to teacher during class, so teacher puts the talking on EXT
but then kid talks more to peers
Look at ratios:
P1 = R1
P2 R1

6. Behavioral Contrast Lets plug in values:
before, talking to teacher highly valuable: P1/P2 = 100/50
now: talking to teacher is not valuable: P1/P2 = 1/50
Alternative is much more "preferable" than in original situation
If alter Ro, get similar changes!

7. Can mathematically predict
Responses
P1 = staying in seat
P2 = out of seat
Rewards
R1 = rewards for staying in seat
R2 = rewards for being out of seat
Ro = reward for playing around in seat
What happens as we vary each of these
P1 = R1/R1+R2+Ro
P2 = R1/R1+R2+Ro

8. Using the matching law Matching law tells us 2 things:
Sensitivity of an animal to changes in reward ratios
Any inherent or incidental bias an animal may have towards one response alternative
We can use the GML to examine differences in reward sensitivity and bias
Across organisms
Across conditions
Across internal states

9. Noncontingent Reinforcement
 Can be a behavioral disruptor OR a technique used to invoke behavior change
An example: Unconditional Positive Regard = free, noncontingent reinforcement
will reduce frequency of undesired responding
BUT, will also reduce behaviors that may want!!!

10. Changing the reinforcer context: 3 alternatives
Increase/decrease rate of contingent reinforcement (increase R1)
Increase/decrease rate of concurrently available reinforcement of one alternative (Decrease R2)
Increase/decrease rate of free, noncontingent reinforcement (Ro).

11. Dealing with Noncontingent reinforcement (Ro)
This can be a nice tool:
works well in rich environments where have more opportunity to alter reinforcement rates.
 Not have to add reinforcers, but can alter rate of contingent reinforcement:
DECREASE contingent reinforcement to both alternatives
Does not alter ratio of reinforcement situation
Can avoid satiation/habituaton
INCREASE NCR for non-target response
E.g.: talking out vs. staying in seat
Give lots of noncontingent reinforcement for any appropriate behavior
Do not have to alter reinforcement for out of seat
invokes satiation/habituation- getting alternative sources of free reinforcers, so why work to get it!?!
allows for contextual changes in reinforcement

12. Effects of Noncontingent Reinforcement: NCR in Humans: Ecott and Critchfield
NCR: Response-independent delivery of a reinforcer (noncontingent reinforcement or NCR)
Become widespread intervention in recent years,
along with extinction, differential reinforcement of other behavior (DRO), and differential reinforcement of alternative behavior (DRA),
Is considered a highly effective and acceptable form of treatment (Carr et al., 2000).
NCR effects appear to be due to both satiation of reinforcer and extinction effects

13. Effects of Noncontingent Reinforcement: NCR in Humans: Ecott and Critchfield
NCR has distinct advantages over these other procedures:
NCR is unlikely to produce side effects sometimes observed during extinction
E.G., response bursting and aggression
Seems to be because NCR does not involve the elimination of access to reinforcers.
NCR often suppresses problem behavior more rapidly than do DRO and DRA
no behavioral requirement for the delivery of reinforcement.
NCR schedules are easier to implement than are DRO and DRA schedules
therapists do not have to carefully monitor the occurrence of either problem or alternative behavior
they simply deliver reinforcers at the appropriate time.

14. Effects of Noncontingent Reinforcement: NCR in Humans: Ecott and Critchfield
BUT: are situations in which NCR may produce undesirable effects.
Get response suppression of other responses now that there is noncontingent reinforcement
Subject may discover that reinforcement is free!
How much or how little NCR is required is debated.
Problems may occur at different stages of treatment:
Initial response suppression
Maintenance,
Acquisition of alternative behaviors,
May require the use of alternative procedures in conjunction with or in place of NCR.

15. Ecott & Critchfield study
6 undergrads; worked up to 10 hours alone in small room with desk, VGA color monitor and mouse
Reinforcers:
Course credit linked to experimental task that established points as reinforcers
Seconds of participation time could be accumulated during experimental tasks
Messages would indicate when points were awarded
Task:
Click here to begin
Screen divided into 2 rectangles with prompt above: total seconds earned this session
Counter started at 0
Each screen region contained small colored square that moved around screen at random directions at 0.5 cm/sec
Click on the moving squares registered as responses
Earned points for time spent responding
8 min sessions, 9-12 sessions per laboratory session

16. Ecott & Critchfield study
Schedules:
When red flashing prompt occurred, click inside a box on center of screen caused 20 s to be added to subject’s total
Baseline: VI 10 s VI 30 s, 2 sec COD
Noncontingent reinforcement sessions:
NCR: reinforcement schedule for alternative behavior remained unchanged,
randomly determined portion of VI 10-s reinforcers that had been contingent on target behavior delivered independent of responding.
100% non contingent
67%
33% 0%
Points for time accrued on their own during this phase (no click to center box needed)
3 subjects had ascending series; 3 subjects had descending series
Used stability criterion

17. Results:
Response rates for target and alternative behaviors across conditions:
4 of 5 participants: as percentage of NCR increased,
Target-behavior rate tended to decrease
Alternative behavior rate increased
5th subject more ambiguous: showed trend on ascending series only
These results similar to prior investigations

18. Results: Alternative reinforcement effects:
Alternative-behavior changes = part of pattern of response competition that resulted in decreased target behavior
To show this: Examine point deliveries in each condition
Look at engagement in 2 types of behavior
Location of response that occurred prior to point delivery, regardless of whether was NCR or CR
When target side converted to NCR: increase rate of point deliveries associated with altnerative bheaivor, decrease target point behavior
As target side point deliveries converted to NCR, # of CR point deliveries decreased and NCR point deliveries increased
Opposite for alternative side point deliveries

19. Deriving a and b Calculated reward sensitivity and bias using the GML
Plotted the log reinforcer ratio (Target/alternative) as a function of the log response ratio (Target/alternative)
Results showed:
Higher a parameter for all participants when NCR point delivers considered in analysis than when omitted
This suggests that NCR point deliveries did contribute to response patterns
That is:
NCR adventitiously strengthened both target and alternative behaviors,
Reductions in target behavior were related to changes in reinforcement of alternative behavior

20. Why is this important? NCR effects are important:
May facilitate both target and alternative responding
But: interplay between the two as use NCR
Changes in target behavior are affected by changes in reinforcement of alternative behavior, and vice versa
Shows importance of context

21. Matching Law in dogs Three HVI dogs Three NHV dogs
Zoomba: Australian Shepherd, age 4, congenitally deaf
Moe: Australian Shepherd, age 3, congenitally deaf, low vision
Keller: Australian Shepherd, age 2, congenitally deaf/blind
Three NHV dogs
Seamus: age 9, golden retriever, normal senses
Harry: age 9 mos, German Sheperd/Alaskan Klee Kai, normal senses
Max: age 2, Australian Shepherd, normal senses

22. Basic set up:
A 4x8 test area was denoted on the middle of the Canine Behavior and Cognition laboratory floor.
The test area was sectioned off into two 4’ x 4’ rectangles using tape to delineate each area.
A chair was placed in each of the two larger rectangles, Two research assistants sat in the chairs, holding a treat cup of dog treats.
The research assistants delivered treats according to the reinforcement schedule outlined below.
A third research assistant will sit approximately 5 feet from the platform and recorded the time the dog spent in each of the 2 rectangles, or time away from the test area using a chess clock timer.
Rectangle 1 Rectangle 2

23. Brief Method Procedure. Training Trials.
Dogs participated in 3 to 5 10-minute sessions at each of the four reinforcement schedules.
Each dog was given 10 to 15 minutes to acclimate to the testing area prior to a testing trial.
Training Trials.
Discrete training trials consisted of the dog being led to each of the two research assistants (seated on the chairs).
When the dog was within the appropriate rectangle, the research assistant provided a food reward
The dog was led to each of the research assistant three times, in random order, such that the dog has the opportunity to sample the available reinforcement for that session.

24. Brief Method Matching Law Trials:
Each trial session consisted of a 10-min. session in which the dog was provided with two food reward opportunities.
Research assistants signaled the availability of a food reward by stomping their foot on the floor (enabling both NVI and HVI dogs to attend to the reinforcer cue).
Food reward was given when the dog entered a rectangle area according to the schedules outlined below.
A contingency was in place such that the dog must enter the rectangle area in order to receive the available reinforce.
The order of the 4 schedules was presented in random order for each of the dogs.
Schedule 1: 1:4 ratio. VI 15 VI 60 sec
Schedule 2: 1:2 ratio. VI 15 VI 30 sec
Schedule 3: 4:1ratio. VI 60 VI 15 sec
Schedule 4: 2:1ratio VI 30 VI 15 sec
The time spent in each rectangle and the number of reinforcers consumed for that rectangle were recorded for each session and for each dog.

25. Results
The average time spent each rectangle and the average number of reinforcers consumed in that rectangle were calculated for each of the four schedules for each dog.
Using the Generalized Matching Law equation, values of reward sensitivity, bias and goodness of fit (r2) were obtained for each of the 6 dogs. These are shown for each dog in figures 1through 6 below.
The mean reward sensitivity, bias and goodness of fit (r2) was obtained for the NVH and HVI groups.
Mann-Whitney U test was used to compare differences in reward sensitivity, bias and goodness of fit (r2) for the two groups.
significant differences between the groups for reward sensitivity (z=-1.96, p=.05)
not for bias (z=0.66, N.S.)
or goodness of fit (r2) (-1.16, N.S.).

27. Conclusions
Results showed that HVI dogs were more sensitive to changes in reward than the NHV dogs.
All the dogs showed good reward sensitivity, that is, their a values approached 1.0.
The HVI dogs showed values consistently higher than 1.0. however.
dogs spent more time at the better alternative than would be predicted by the scheduled ratio of reinforcers.
That is, they valued the choice with the higher rate of reward as more valuable than predicted. This is called overmatching.
Overmatching occurs when the subject appears to be "more sensitive" to the differences in reinforcement between the two alternatives than when matching occurs.
Supports hypothesis that HVI dogs should be more attentive and thus more sensitive to changes in reward ratio than NHV dogs.
HVI dogs should be more attentive because they lack normal vision and hearing input
Hyper-attend to their environment.
Given that the HVI and NVH dogs should not differ genetically, these differences must be due to differences in experience as a result of the differences in perceptual ability.
Results also support previous data from out laboratory
HVI dogs attend more to humans for a pointing task, and a bigger/smaller choice task.
HVI dogs are more strongly attached to humans and show greater separation anxiety.
HVI dogs show deficits in social interactions during play both with HVI and NHV dogs.

28. Applying the GML to Antisocial Behavior
Negative reinforcement plays important role in development and maintenance of aggressive and antisocial behavior
Preschooler, school aged boy’s aggressive behavior in interactions with mother
Maintained by TERMINATION of maternal behavior that otherwise would have caused conflict to continue
E.g.,: demand for compliance

29. Applying the GML to Antisocial Behavior
By adolescence: antisocial behavior well shaped
Preschool years:
coercion
Termination of demands from peers/teachers when acted aggressively
School years: behavior continues to be reinforced
By adolescence: peer interactions become most important, more than teachers

30. Interesting Change in reinforcement
Shift in reinforcement ratio
Preschool: Proportion of time allocated to interactions with peers correlates with proportion of positive peer interactions
School years: begin shift towards relation between time allocated to interaction with peers becomes correlated with negative peer interactions
By adolescence: this is negative pattern is well established
Is a shaping process! Learning to use antisocial behavior via interactions with parents, teachers, peers.

31. So what does this mean?
Negative social reinforcement maintains antisocial behavior in a manner that can be described by the matching law
Acting bad gets you out of things
Positive social reinforcement also maintains antisocial behavior and can be described by the GML
Acting bad gets you things
These reinforcement contingencies develop over the child’s reinforcement history

32. McDowell and Caron: GML and Antisocial boys
Oregon Youth Study
Behavior broken into 2 categories
Rule-breaking
Normative
The equation accurately described rule-break vs. normative talk of the boys
Accounted for 87-97% of the variance!

33. Proportion of rule-break talk as a function of obtained
Reinforcement proportion for rule-break talk

34. Exponents a and b plotted as a function of child deviance quartiles

35. Conclusions about deviance behavior
GML described the relationship between deviant behavior and reinforcement well
Reward sensitivity decreased as child deviance scores increased!
Suggests that the more deviant the boy, the less the boy preferred positive reinforcement for normative talk
Again suggests that history important: long history of attention and negative reinforcement for rule break behavior may lessen sensitivity to positive reinforcement as child becomes more deviant

36. Conclusions about deviance behavior
Boys’ verbal behavior was strongly biased towards normative talk! Likely due to:
Positive reinforcement for normative talk
Punishment for rule-break talk
Bottom line: if the pattern of negative reinforcement/punishment can be altered, then this may alter the likelihood of a child developing more antisocial tendencies!

37. Conclusions: Clinical applications of the GML
MUST consider broader environmental conceptualizations of problem behavior
Must account for sources of reinforcement other than that provided by therapist
again- Herrnstein's idea of context of reinforcement
if not- shoot yourself in the old therapeutic foot

38. Take Home Message:
It is the disparity between 2 relative rates of reinforcement that is important
Must consider Ro
Context matters!