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| Basic Research Models of Clinical Disorders and Clinical Treatments |
| Tuesday, May 30, 2006 |
| 12:00 PM–1:20 PM |
| Manila |
| Area: EAB; Domain: Basic Research |
| Chair: Timothy R. Vollmer (University of Florida) |
| CE Instructor: Timothy R. Vollmer, Ph.D. |
| Abstract: In this series of presentations, basic research models that relate directly to clinical disorders and clinical treatments are described. In the first paper, Michael H. May will report on a study showing that access to aggression functions as reinforcement in mice. Schedule control characteristic of common reinforcement schedules were obtained. In the second paper, Maria H. Couppis will examine the hypothesis that mesocorticolimbic dopamine modulates the reinforcing properties of aggression in mice. In a third paper, Kimberly Sloman, using a rat operant model, compares three reinforcement schedules commonly used as behavioral treatments for severe behavior disorders. The schedules include differential reinforcement of other behavior, fixed time, and momentary differential reinforcement. In the fourth paper, Andrew Samaha, also using a rat model, will present data showing the effects of various reinforcement contingency values on lever pressing. In addition, he will present a method for extending the research to humans. |
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| Schedule Analyses of Aggression as a Positive Reinforcer. |
| MICHAEL MAY (Vanderbilt University), Maria H. Couppis (Vanderbilt University), Craig H. Kennedy (Vanderbilt University) |
| Abstract: Violent behaviors, such as aggression, appear in most phyla and seem to serve an adaptive function. However, the appearance of these behaviors in human beings can be associated with a range of detrimental societal outcomes. For people with developmental disabilities, the occurrence of aggression is associated with placement in more restrictive residential and educational settings and a diminished quality of life. Although a great deal of preclinical research has been done on the neurobiology of aggression, little is known about the operant characteristics of these behaviors and the neurobiology that might underlie their occurrence. It is plausible that a better understanding of possible reward mechanisms related to aggression may lead to improved behavioral and/or pharmacological treatments. An important first step in pursuit of this goal is to isolate aggression as an operant response that can be studied in its own right. In this presentation, we present data on aggression as a positive reinforcer for an arbitrary response (i.e., nose poking) in mice. The experiments used Male Swiss-Webster mice in the resident-intruder paradigm. Initially, mice were taught to nose poke as an operant response to earn liquid. Once stable patterns of responding were established, the liquid was withdrawn as a consequence and a novel intruder mouse was introduced when the response contingency was met. We obtained response patterns characteristic of fixed-ratio, fixed-interval, and DRL reinforcement schedules suggesting that access to aggression functioned as a positive reinforcer. Tests using a progressive-ratio reinforcement schedule showed a “break point” significantly lower than for liquid reinforcement, suggesting that access to aggression was a lesser valence stimulus than liquid. Our findings provide a potential model system and experimental paradigm for analyzing the neurobiology of aggression within the context of its stimulus properties as a positive reinforcer. |
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| Role of the Nucleus Accumbens in the Positively Reinforcing Effects of Aggression. |
| MARIA H. COUPPIS (Vanderbilt University), Michael May (Vanderbilt University), Craig H. Kennedy (Vanderbilt University) |
| Abstract: Behavioral research suggests that aggression serves as a positive reinforcer. However, the brain mechanisms underlying aggression as a reinforcer remain to be determined. This study examined the hypothesis that mesocorticolimbic dopamine in the nucleus accumbens (NAc) modulates the reinforcing properties of aggression. ‘Resident’ male mice were trained to perform a nose-poke task on a VR-5 schedule for the opportunity to aggress toward an ‘intruder’ mouse. After obtaining a stable baseline nose-poke rate, in vivo micro-infusion of 3 different doses of dopamine receptor (DR) 1 and DR2 antagonists, SCH-23390 and Sulpiride, were administered into the NAc. Sulpiride reduced responding at all three doses and did not affect movement at the low and medium doses. SCH-23390 lowered responding at medium and high but was accompanied by reduced movement. These data suggest that mesocorticolimbic dopamine does modulate aggression as a reinforcer though pharmacological manipulation in humans may be limited by motor side effects. |
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| A Laboratory Comparison of Differential Reinforcement of Other Behavior (DRO), Noncontingent Reinforcement (NCR), and Momentary DRO. |
| KIMBERLY SLOMAN (University of Florida), Timothy R. Vollmer (University of Florida), Andrew Samaha (University of Florida) |
| Abstract: Differential reinforcement of other behavior (DRO) and noncontingent reinforcement (NCR) are commonly used treatments to decrease aberrant behavior. Some previous research has reported problems with these treatments including the occurrence of extinction bursts (DRO), adventitious reinforcement (NCR), and difficulty with implementation (DRO). During momentary DRO, a reinforcer is delivered if responding is absent in the last portion of an interval. Thus, momentary DRO may prevent adventitious reinforcement and may also minimize the occurrence of extinction bursts while maintaining the "ease of implementation" associate with NCR. The purpose of the present experiment was to evaluate DRO, NCR, and momentary DRO in a laboratory using rats. The treatments were evaluated within subject using multielement and reversal designs. Dependent measures included rate of responding, highest response point, average of first and last five points of the condition, and rate of reinforcement. Preliminary findings suggest that all of the treatments were effective in reducing response rates. However, overall response rates and highest response point were somewhat lower in the momentary DRO condition. Implications for implementation of momentary DRO in applied settings will be discussed. |
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| Animal and Human-Operant Models of Common Behavioral Treatments. |
| ANDREW SAMAHA (University of Florida), Timothy R. Vollmer (University of Florida), Kimberly Sloman (University of Florida) |
| Abstract: Using rat and human operant preparations, contingency values of various strength were arranged by altering the probability of a reinforcer given a response and the probability of a reinforcer given no response. A positive contingency (random-ratio like) was programmed by arranging a higher probability of a reinforcer following periods with responses (lever press for rats, computer key pressing with a target for humans) than following periods without a response. Negative (DRO like) contingencies followed the opposite pattern. In general, responding maintained under positive contingencies and decreased under negative contingencies. However, the effects of positive and negative contingency conditions depended on the strength of the contingency in the prior condition. These results have implications for applied behavior analysis in terms of arranging contingencies in skill acquisition (positive contingencies following a history of neutral or negative contingencies) and behavior reduction (negative contingencies in differential reinforcement of other behavior following a long history of positive contingencies for problem behavior). |
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