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Two successive studies were conducted to determine the possibility of operant reinforcement of nonspecific galvanic skin resistance responses. In the first study, with five experimental and three control subjects who served for 20 to 30 min a day for 10 days, all experimental subjects learned to emit more nonspecific galvanic skin resistance responses than their ad hoc matched controls. In a second study, nine experimental and nine control subjects were matched for first‐day levels of reactivity and yoked for operant reinforcement schedules. Significant differences between the two groups were found on the last day of conditioning and during extinction. Six of the nine experimental subjects showed higher cumulative rate curves than their matched and yoked controls. The concomitant measures (basal resistance, heart rate, etc.) all supported this finding. It was suggested that operant reinforcement of autonomic response tends to maintain a certain level of responding in contrast to persistent adaptation in the control group.

During one stimulus, food rewards and electric shocks were intermittently delivered to rats regardless of their behavior. Subjects could either terminate or initiate this stimulus by pressing a lever. Effects of the relative frequency of food and shock were studied by manipulating the variable‐interval schedules associated with each. Increases in the relative frequency of shocks led to decreases in the amount of time each rat spent in the stimulus. Subjects initiated and terminated the stimulus most often at intermediate relative frequencies of food and shock, rather than in situations where the conditions were either very favorable (e.g., only food was possible) or very unfavorable (e.g., only shock was possible). This technique thus provides quantitative data on oscillatory behavior during conflict which confirm and extend results previously obtained by qualitative observation.

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Pigeons' pecks on one key produced a stimulus correlated with a mixed‐ratio schedule of food reinforcement. Pecks on a second key produced a stimulus correlated with a fixed‐ratio schedule. When the arithmetic mean of the mixed ratios equaled the fixed ratio, the former stimulus maintained a higher rate of pecking. When the fixed ratio was sufficiently smaller, preference shifted to it. The pigeons' relative preference for the schedules could be described by comparing the geometric mean of the reinforcement rates in the several mixed‐ratio components with the reinforcement rates in the fixed‐ratio components.

Uninstructed subjects choose to view, in sharp focus where possible, projected visual images in preference to various simpler auditory and visual stimuli (e.g., buzzers of flashing lights). The rate of responding on the lever rapidly increased above the operant level (projector inoperative) even though the stimuli were nonsense syllables. When focusing also was made contingent on responses, the subjects promptly started sharpening the focus of legible but blurred nonsense syllables. When the visual material was colored landscape scenes, the rates of slide‐changing generally decreased, because of increased viewing time relative to the nonsense syllables, at the same time that the latencies of focusing decreased. Both the sharpness of focus and the total time spent with the image in sharp focus increased greatly with the colored slides, establishing that the subjects were under control of the stimulus events. Extinction of both responses occurred very rapidly when the controls became inoperative.

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