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The effect of several reinforcement schedules on the variability in topography of a pigeon's key‐peck response was determined. The measure of topography was the location of a key peck within a 10‐in. wide by 0.75‐in. high response key. Food reinforcement was presented from a magazine located below the center of the response key. Variability in response locus decreased to a low value during training in which each response produced reinforcement. Variability increased when fixed intervals, variable intervals, random intervals, or extinction were scheduled.

Data are presented which indicate that lever‐pressing behavior of a profoundly retarded child could be reinforced by the contingent application of vibratory stimulation for each response. With vibration available 24 hr per day, no decrement in daily rate of responding for vibration was seen over a three‐week period. Suggestions are made for further use of this finding in working with the profoundly retarded.

A 16‐yr‐old retarded male, diagnosed organically blind and treated by those around him as a blind person, was given practice in discriminating visual stimuli. After training, he responded with significantly better than chance accuracy in a choice situation in which stimuli were as small as 18 pt Futura Medium type. In addition, he was trained to look at the experimenter's eyes when instructed to do so. Control procedures revealed that it was the reinforcement contingency that functioned to establish and maintain eye contact. Eye contact with the experimenter generalized in a limited way to situations in which this behavior was not reinforced, though not to a neutral individual. When the boy was required to use visual cues to help himself in a cafeteria line, he soon emitted the necessary behaviors, where formerly he had been assisted by others. Resumption of assistance markedly decreased self‐help, suggesting that continued use of any newly learned skills would depend on the response of the individuals in his environment. The boy also learned eating behavior that appeared to require the use of visual cues.

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In the first of two experiments, three cotton rats (Sigmodon hispidus) and three albino rats were exposed to instrumental escape, unsignaled avoidance, and signaled avoidance, in that order. All subjects learned the escape procedure quickly, with the albino rats having generally shorter latencies, higher response rates, and requiring fewer sessions to reach the criterion. When the avoidance contingency was introduced, the cotton rats continued to respond almost entirely in the presence of the shock, whereas the albino rats responded in its absence, thus displaying effective avoidance behavior. Introduction of a pre‐aversive stimulus did not improve the performance of the cotton rats. In the second experiment, five cotton rats and four albino rats were exposed to a free‐operant (Sidman) avoidance procedure with a shock‐shock interval of 3 sec and a response‐shock interval of 20 sec. The cotton rats initiated responding at lower shock intensities than the albino rats, but their asymptotic avoidance responding was far less effective.

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The Brown‐Jenkins auto‐shaping procedure for pigeons was found applicable to monkeys. Repeated pairings of lighted keys with reinforcement generated key‐pressing behavior. The animals rapidly learned a simultaneous light‐dark discrimination. The topographies of key‐pressing and magazine behavior differed; the food tray was not illuminated.