Association for Behavior Analysis International

Behavior analytic interpretations of subjective experience rest upon discrimination of complex relations between environmental stimuli and behavior. Often those discriminations involve interoceptive, private stimuli or spatiotemporally diffuse relations between public stimuli and behavior. This session will be composed of three papers assessing basic research questions related to discriminative control by these complex stimuli. Kangas describes similarity and differences of delta-9-tetrahydrocannabinol (THC) and anandamide in subjective drug effects and behavioral performances on a remembering task. Jewett explains how a food deprivation discrimination task is used to determine what compounds or nutrients produce subjective states correlated with food deprivation (i.e., hunger) or satiety. Brooks demonstrates how an apparent failure of exteroceptive stimulus control can be understood when subjects responding are shown to be an orderly function of the longest schedule requirement in a variable-interval schedule. The results of these basic behavioral studies can provide the empirical grounding for interpretations of consciousness and self-awareness in everyday situations and perhaps inform our understanding of clinically relevant behavior problems.

The present talk will describe a novel application of discrimination techniques to further our understanding of the processes associated with the regulation of food intake. We trained rats to discriminative between 22 and 2 hours acute food deprivation in a two-choice operant task. After acquisition of the discrimination, generalization tests were conducted with a variety of orexigenic (feeding-inducing) and anorectic (feeding-suppressing) compounds to determine to what extent compounds that affect food consumption also alter or mimic the discriminative stimulus effects of acute food deprivation. Other tests involved medications with current clinical uses in humans. Results will be discussed both in terms of pharmacological and nutritional mechanisms of action. Results of generalization tests assessing the ability of solid and liquid solutions to alter the discriminative stimulus effects of acute food deprivation will also be discussed. Our findings indicate discrimination tasks can be used to further the understanding of normal biological processes, and these results may also complement the search for better therapeutics.

Stimulus compounding is a procedure in which two or more discriminative stimuli, trained separately, are presented simultaneously in probe sessions and typically results in summated response rates of the compound components. The purpose of this study was to produce the compounding effect of additive summation using stimuli that, during training, alternated daily rather than within the session as is more traditionally done with multiple schedules. Six Sprague-Dawley rats were trained to lever press under a variable-interval 60-s schedule in the presence of either a light or tone stimulus, with the absence of the light and tone signaling extinction. Sessions featuring light or tone alternated daily and were separated by extinction sessions. After extensive training on this procedure, compound probes revealed no evidence of additive summation when the light and tone were presented together. Subjects responded steadily during extinction sessions until a length of time equal to the longest interval of the variable interval schedule had elapsed, at which point responding ceased. Although responding was intended to come under control of exteroceptive tone and light stimuli, it appears that the longest constituent schedule within the array of VI values gained control over responding via acquisition of a more abstract temporal discrimination.