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The present study was designed to explore whether motivational procedures are needed to maintain a retardate's continued use of previously trained eating skills. A profoundly retarded child who ate food with her hands was trained by a manual guidance procedure to eat properly with a spoon, but the child still did not use the spoon after having learned to do so. When a motivational‐maintenance procedure was applied, the child did begin to eat properly. When maintenance was discontinued, the child returned to eating with her hands. Proper eating returned when maintenance was applied again; when discontinued, the child returned to eating with her hands. These results demonstrate that continued motivational procedures are needed after training to maintain the retardate's continued use of proper eating skills.

Four‐year‐old children were tested on letter discrimination. Subjects in two experimental groups went through an experimental training program on a match‐to‐sample apparatus. Subjects in the experimental‐critical group were given reinforcers for responding to features of the stimuli thought critical for discriminating letters while subjects in the experimental‐noncritical group were given reinforcers for responding to noncritical features. Subjects went through the training program daily until they reached criterion; then they were posttested on letters. Subjects in a control group received no training but were posttested. Subjects in all groups made fewer errors on the posttest. Subjects in the experimental‐critical group made significantly fewer posttest errors than subjects in the experimental‐noncritical group, lending support to the hypothesis that reinforcement of discriminative responding to critical features of letter‐like stimuli results in greater improvement in letter discrimination than reinforcement of discriminative responding to noncritical features of stimuli. Analysis of confusion matrices provided tentative indications of the nature of letter confusions in 4‐yr‐old children.

Two mothers of deviant young children were instructed to count their episodes of attention to appropriate child behavior in their homes, using wrist counters. Attention and appropriate child behavior were defined before counting began. Independent observations of parent‐child interactions showed that, for each mother‐child pair, the percentage of maternal attention given following appropriate child behavior increased, as did the child's appropriate behavior. Removal of the counters did not produce a reversal of the behaviors; instead the increased level stabilized. One mother was then instructed to count her attention to inappropriate child behavior and to decrease it. This instruction had little effect on her attention, and her child's behavior did not change. When both parents were again instructed to count their episodes of attention to appropriate behavior, further improvements in both mothers, and in their children resulted. These results were obtained despite inaccurate parent self‐recording. Follow‐up observations made over the next five months showed these behavioral gains to be durable. A third parent and his child were unaffected by this training procedure. Thus, there are instances in which self‐recording may function as an effective and economical parent‐training technique for effecting improvements in child behavior.

Many profoundly retarded children continue to crawl even though they can walk. Crawling and walking were viewed as two alternative response modes, both reinforced by movement. Children choose the one mode that is easier and faster for them. A training program was designed to increase the ease and speed of walking relative to that of crawling, and consisted of restraint‐for‐crawling and priming‐of‐walking. With the program, four retarded children reduced crawling and began to walk instead. When training was discontinued, two children with moderate walking impairment continued to walk rather than crawl. Two children with severe impairment of walking, however, required the occasional use of the restraint procedure to maintain walking as the dominant mode of locomotion. The program was easily administered, required little time, and was effective for all four children.

Pigeons' pecks in the presence of two concurrently available initial‐link stimuli occasionally produced one of two stimuli associated with mutually exclusive terminal links. Pecks during either terminal link produced food according to aperiodic (variable‐interval and variable‐ratio) or periodic (fixed‐interval and fixed‐ratio) schedules of reinforcement. Aperiodic and periodic schedules to which the pigeons were indifferent, in the sense that these schedules maintained equal responding in the initial links, often yielded different preferences in separate choice tests with a third schedule. Conversely, aperiodic and periodic schedules that were equally preferred to a third schedule often failed to generate indifference. These intransitivities imply that (1) aperiodic and periodic schedules are not functionally equivalent in their effects upon choice, and (2) efforts to find a simple method for transforming aperiodic schedules into their periodic equivalents will fail.

Pigeons emitted almost exclusively short‐duration key pecks (shorter than 20 msec) when on negative automaintenance procedures, in which pecks prevented reinforcement. Peck durations under fixed‐interval and fixed‐ratio reinforcement schedules were generally two to five times longer than pecks under a negative automaintenance schedule. However, initial key pecks were of short duration, independent of procedure. The frequency of short‐duration pecks was insensitive to differential reinforcement, while the frequency of long‐duration pecks was sensitive to differential reinforcement. It is proposed that short‐duration pecks arise from the pigeon's normal feeding pattern and are directly enhanced by food presentation, while long‐duration pecks are controlled by the contingent effects of food presentation. The implications of the existence of two classes of pecks for the functional definition of operants and the separation of phylogenetic and ontogenetic sources of control of key pecking are discussed.

Rats were trained to press a lever under schedules of food postponement. In the absence of lever presses, food was delivered periodically (food‐food interval). Responses initiated a second interval (response‐food interval) that was reset by each additional response. Performance was first studied at different response‐food intervals with the food‐food interval fixed at 30 or 60 sec, or 10 min. Response‐food intervals were examined in ascending order and then recovery was studied at shorter intervals. Finally, the food‐food interval was manipulated with response‐food interval fixed at 30 sec. At food‐food intervals of 30 and 60 sec, responding first increased and then decreased as the response‐food interval increased. At the 10‐min food‐food interval, responding decreased with increasing response‐food interval. In general, very low rates of responding occurred when the response‐food interval was 60 sec or more and when it equalled or exceeded the food‐food interval. However, responding was maintained in one animal when the food‐food interval was decreased from 120 to 15 sec with the response‐food interval at 30 sec. Results, in terms of several dependent variables, are compared with data on shock avoidance. Effects of response‐independent and response‐produced food and shock are discussed.

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