Age differences in autonomic nervous system response patterns were investigated to determine if there was an age-related increase in the tendency to respond to multiple stimuli with a consistent response hierarchy (individual consistency). Five stimuli were administered in a Latin Square design-mental arithmetic, cold pressor. isometric exercise, comic slide, and time estimation. A warning tone was presented before each stimulus. Physiological measures included heart rate, systolic and diastotic blood pressures, skin potential, breathing rate, and digital blood flow. To compare responses in different systems, responses were standardized according to the formula, Z = |50 + 10 (X -M )]/a, where Z is the standardized score, X is the difference between stimulation and warning levels, M is the average response for that system, and a is the square root of the mean square for error from the analysis of variance computed for each response system. A matrix was generated for each subject which included his Z scores from the six response systems for the five stimuli. Intraclass correlations were then computed. Individual consistency significantly increased with increasing age (r= .33,p<.005).

Six adult male research volunteers, in two groups of 3 subjects each, lived in a residential laboratory for 15 days. All contact with the experimenters was through a networked computer system, and subjects' behavior was monitored continuously and recorded. During the first part of each day, they were allowed to socialize. Two cigarettes containing active marijuana (2.7% delta 9-THC) or placebo were smoked during the private work period and the period of access to social activities. Three-day contingency conditions requiring subjects to engage in a low-probability work activity (instrumental activity) in order to earn time that could be spent engaging in a high-probability work activity (contingent activity) were programmed during periods of placebo and active-marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that subjects spent engaged in the low-probability instrumental activity and decreased the time spent engaged in the high-probability activity. During active-marijuana administration, however, the increases in instrumental activity were consistently larger than observed under placebo conditions. The decreases in contingent activity were similar to those seen under placebo conditions. Smoking active marijuana was thus observed to produce increments in instrumental activity under motivational conditions involving contingencies for "work activities."

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We evaluated methods for comparing the effects of dextroamphetamine (Dexedrine), thioridazine (Mellaril), and contingency management in the control of severe behavior problems. A reversal design was used in which medications were systematically titrated and assessed in unstructured as well as structured settings with three clients. Subsequently, behavioral procedures including timeout, differential reinforcement of other behavior, and visual screening, were used in a multiple-baseline design across settings. The assessment and design methods were useful in comparing the interventions. Dextroamphetamine decreased inappropriate behaviors and improved academic behaviors in one client, but no reliable effects were observed in the other two clients. Thioridazine was variable across clients, settings, behaviors, and dosages. Contingency management produced consistent decreases in inappropriate behaviors and small improvements in academic performance.