Indexador

Resumo não informado pela fonte indexada.

A behavioral measurement system was designed around a point economy for a psychiatric ward of delinquent patients. The characteristics of the system were: (1) the records of points earned for appropriate patient behavior formed the primary data. (2) After the points were recorded in a data matrix, graphs were prepared to show the behavior of individual patients, the participation of the patient group in the various ward activities, and an overall index of ward operation. (3) Several techniques were devised for reviewing the graphs so that the ward staff could evaluate the success of their procedures over substantial time periods.

An instrument that assists subjects in attaining deep muscle relaxation by means of analog information feedback is described. Subjects hear a tone with a pitch proportional to the electromyographic activity in a given muscle group. Results showed that subjects receiving this type of analog feedback reached deeper levels of muscle relaxation than those receiving either no feedback or irrelevant feedback. The basic method employed—electronic detection, immediate information feedback, and systematic shaping of responses—would seem potentially applicable to a variety of physiological events, and might be useful both in behavior therapy and in certain psychosomatic disorders.

In the presence of one click frequency, the presses of two hungry rats on one of two levers were reinforced with food on variable‐interval schedules; in the presence of a different click frequency, presses on the other lever were reinforced. In stimulus generalization tests, a variety of click frequencies were presented and reinforcement withheld. The test stimuli were found to exert control over which of the two levers the rats pressed, but not over the rate of pressing the selected lever. The results were interpreted as further evidence that intermediate rates in generalization gradients may be the result of the alternation of several distinct behavior patterns.

Language training procedures, which involved positive reinforcement for verbal imitation, were applied to increase the appropriate verbal behavior of an almost non‐verbal, brain damaged, 5‐yr‐old boy. Two experiments assessed the effectiveness of timeout from positive reinforcement as a training procedure viewed as having potential punishing and negatively reinforcing functions. In both experiments, timein, termination of timeout and resumption of training, was arranged to have reinforcing properties in that it presented an opportunity to receive positive reinforcers. In Exp. I, the procedure consisted of temporarily halting language training (timeout) following verbal jargon and resuming it (timein) contingent upon the boy sitting quietly in his chair for approximately 30 sec. The jargon declined to almost zero for an extended period each time the procedure was employed. In Exp. II, the procedure consisted of halting language training (timeout) after emission of undesired verbal responses which previously had been reinforced as the desired approximation to the target verbal behavior. Resumption of training (timein) was made contingent upon the emission of the then‐desired approximation of the target verbal behavior. In each experiment, the contingent timeout and timein of the language training that involved positive reinforcement effectively reduced the undesired and increased the desired responses.

Pigeons were exposed to a procedure in which food was presented after a fixed period of time had elapsed, provided no attack against a nearby stuffed pigeon had occurred during the last 15 sec of the period. As the minimum inter‐food interval was increased logarithmically through seven values from 15 sec to 960 sec, attack increased to a maximum and then decreased. For both pigeons, attack predominantly occurred after, rather than shortly before, food deliveries.

A conditional discrimination was established and analyzed, using four pigeons. The discrimination was among four compound stimuli projected on the response key—a white circle or triangle on a red or green background—during two conditions of illumination in the chamber, no illumination or flashing illumination. The two lighting conditions indicated whether the stimuli on the key containing triangles or those containing red would be the occasion for reinforcement. After the discrimination formed, generalization to intermediate and extreme values of the conditional stimulus and the attention of the birds to separate aspects of the stimulus on the key under each of the conditional stimuli were studied. All subjects generalized across values of the conditional stimulus, the lighting of the chamber. But subjects differed in the manner in which they treated the compound stimuli: two tended to attend to one or the other aspect of the stimulus on the key depending on the conditional stimulus, and two offered no evidence of such selective attention. Thus, the differential control of responding by the conditional stimuli cannot be attributed to a shift in attention between the figure and ground aspects of the compound stimuli.

Pigeons exposed to gradually increasing intensities of pulsing electric shock pecked a key and thereby reduced the intensity of shock to zero for 2 min. Acquisition of key pecking was brought about through an autoshaping process in which periodic brief keylight presentations immediately preceded automatic reduction of the shock. On the occasions of such automatic reduction of shock preceding the first measured key peck, little or no orientation to the key was observed. Observations of pigeons with autoshaping of positive reinforcement also revealed little evidence of orientation toward the key.

If a response key is regularly illuminated for several seconds before food is presented, pigeons will peck it after a moderate number of pairings; this “auto‐shaping” procedure of Brown and Jenkins (1968) was explored further in the present series of four experiments. The first showed that pecking was maintained even when pecks turned off the key and prevented reinforcement (auto‐maintenance); the second controlled for possible effects of generalization and stimulus change. Two other experiments explored procedures that manipulated the tendency to peck the negatively correlated key by introducing alternative response keys which had no scheduled consequences. The results indicate that pecking can be established and maintained by certain stimulus‐reinforcer relationships, independent of explicit or adventitious contingencies between response and reinforcer.

Bobwhite quail were given extended auto‐shaping, a procedure in which response‐key illumination or color change is paired with response‐independent food presentations. Continuation of the auto‐shaping procedure yielded increased responding across sessions, although responses were never instrumental in producing food. The quail were shifted directly from the auto‐shaping procedure to a variable‐interval 60‐sec schedule of reinforcement. All three birds were approaching stable response rates by the fifth session on the variable‐interval schedule.