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In these experiments, the rats became less impulsive after acute non-disruptive doses of pre-session METH, whereas they became more impulsive after receiving repeated post-session injections of a dose that was behaviorally disruptive when administered acutely.

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Peak deviation analysis is a quantitative technique for characterizing interresponse-time distributions that result from training on differential-reinforcement-of-low-rate schedules of reinforcement. It compares each rat's obtained interresponse-time distribution to the corresponding negative exponential distribution that would have occurred if the rat had emitted the same number of responses randomly in time, at the same rate. The comparison of the obtained distributions with corresponding negative exponential distributions provides the basis for computing three standardized metrics (burst ratio, peak location, and peak area) that quantitatively characterize the profile of the obtained interresponse-time distributions. In Experiment 1 peak deviation analysis quantitatively described the difference between the interresponse-time distributions of rats trained on variable-interval 300-s and differential-reinforcement-of-low-rate 72-s schedules of reinforcement. In Experiment 2 peak deviation analysis differentiated between the effects of the psychomotor stimulant d-amphetamine, the anxiolytic compound chlordiazepoxide, and the antidepressant desipramine. The results suggest that peak deviation analysis of interresponse-time distributions may provide a useful behavioral assay system for characterizing the effects of drugs.

Children with fetal alcohol spectrum disorder (FASD) are often diagnosed with attention-deficit/ hyperactivity disorder (ADHD). These children show increases in reaction time (RT) variability and false alarms on choice reaction time (CRT) tasks. In this study, adult rats prenatally exposed to ethanol were trained to perform a CRT task. An analysis of the distribution of RTs obtained from the CRT task found that rats with a history of prenatal ethanol exposure had more variable RT distributions, possibly because of lapses of attention. In addition, it was found that, similar to children with FASD, the ethanol-exposed rats had more false alarms. Thus, rats with prenatal ethanol exposure show attention deficits that are similar to those of children with FASD and ADHD.