Effects of d-amphetamine on self-aggression and posturing in stumptail macaques

The behavioral effects of d-amphetamine sulfate were studied in adult male stumptail macaques living within a large heterogeneous group in an outdoor enclosure. Among five subjects that received a range of doses (.01 to .3 mg/kg), d-amphetamine increased self-aggressive behavior and abnormal posturing in subjects that exhibited these types of behavior prior to drug administration, but it had no effect in subjects not exhibiting those activities in the absence of the drug. For the former subjects, the dose-effect curves for self-aggression were of an inverted U-shape analogous to the effect of d-amphetamine on schedule-controlled behavior. Over the range of doses studied, the curve for abnormal posturing was monotonic. The data indicate that d-amphetamine can have effects on untrained behavior in individual animals in a quasinatural environment that are qualitatively and quantitatively similar to the behavioral effects observed in other laboratory environments, and that d-amphetamine does not evoke or increase a behavioral response in individual subjects that do not exhibit the response in the absence of the drug.     

Does reward depletion influence spatial memory performance?

If spatial memory tasks are considered as foraging problems, it can be predicted that rats' difficulty in learning a win-stay task—revisiting part of a maze where food has recently been found—should be partly overcome if the food is not fully consumed at the first visit (nondepleted reward) rather than being all eaten (depleted reward). Three experiments confirmed and further analysed this result. Experiments 1 and 2 showed that it does not depend on the amount of food initially found; nor is win-stay performance affected by the amount of food actually eaten. Experiment 3 suggested that the effects of nondepleted reward are mainly due to the animals' being interrupted while eating, and very little to the fact that uneaten food is left behind. The results are discussed with regard to their implications for learning theory, and for the application of foraging theory to learning and memory experiments.     

Probabilistic contingency theories of animal conditioning: A critical analysis

Seven contingency theories of classical and instrumental conditioning were defined in relation to the contingency matrix and to six separate probabilities which can be derived from this matrix. These theories were compared on the basis of formal similarities and differences, and were judged against three separate empirical variables which have been discussed in the contingency literature: the duration of the intertrial interval, partial reinforcement, and negative contingencies between the two events of conditioning. All previous theories had some difficulty predicting the effects of one or more of these variables upon animal conditioning. Also, some formulas make the unusual prediction that there will be less conditioning when there is more than one conditioning trial. The paper concluded with an extensive discussion of the problems that are created by conditioning events with temporal extension; events which are then categorized by a contingency matrix which has no temporal character. Some possible solutions to the problems were discussed.     

Test of reliability of perception of parental and childhood illness behavior

This report details the reliability of perceived parental and childhood illness behavior. Three versions of the Illness Behavior Inventory were created to assess perceived illness behavior of one's mother, father, and oneself as a child. The measures were administered twice to 32 students of linguistics at a major university with a 2-wk. interval between administrations. Each measure across administrations correlated highly and significantly (.98 to .99). It was concluded that perceptions of parental and childhood illness behavior are reliable over time but their sensitivity to actual historical events remains an empirical question.