Indexador

Five pigeons whose key pecking was maintained by 4‐sec access to grain on a variable‐interval 2‐min schedule received Pavlovian differential conditioning trials superimposed upon the instrumental baseline. The conditioned stimuli were changes in the stimulus on the key from white to red, or to a white horizontal line against a dark background. The positive conditioned stimulus was 20 sec long, and was followed immediately by 8‐sec access to grain. The negative conditioned stimulus, also 20 sec long, was never paired with response‐independent food. All pigeons responded more rapidly in the presence of the positive conditioned stimulus than in the presence of the negative one. The positive conditioned stimulus produced an increase in response rate over the pre‐conditioned stimulus period. The negative conditioned stimulus had no marked effect upon response rate. When the roles of the positive and negative stimuli were reversed, and the duration of the response‐independent reinforcement was reduced to 4 sec, the new positive conditioned stimulus came to facilitate responding, and the new negative conditioned stimulus no longer produced facilitation. A second discrimination reversal produced similar outcomes. When a third reversal was initiated, and the duration of response‐independent reinforcement was reduced to 2 sec, the difference between the effects of the positive and negative stimuli diminished.

Responses by rats were reinforced with food under a second‐order schedule involving fixed‐ratio reinforcement of temporally spaced responses. Requirements of 20, 8, and 3 responses were examined. The typical characteristic of spaced responding was maintained under the ratio schedules: interresponse time distributions were similar to those typically seen, and were not noticeably affected by the ratio value. Comparison of total response rate, correct response rate, and accuracy showed correct response rate to be the most consistently affected by changes in the ratio value. Substantial evidence of schedule control was seen only for correct responses. Incorrect response records were erratic, but rates generally declined as reinforcement was approached. Correct response records were characterized by increasing rate as reinforcement was approached. It was suggested that the pattern of fixed‐ratio performance revealed may be affected by the behavioral unit examined.

Resumo não informado pela fonte indexada.

Resumo não informado pela fonte indexada.

Resumo não informado pela fonte indexada.

Resumo não informado pela fonte indexada.

Resumo não informado pela fonte indexada.

Resumo não informado pela fonte indexada.

Head Start children were matched into two groups on the basis of rates of disruptive behavior during rest periods. Attempts were made to modify their behavior using either individual or group token reinforcement procedures. While the reinforcement procedures reduced inappropriate behavior somewhat, the addition of instructions to the reinforcement reduced the inappropriate behavior to near zero for both groups. Instructions alone, however, were ineffective in controlling behavior. Type of reinforcement (group or individual) did not produce differential effects. While experimental control over the target behavior was demonstrated, there was little carryover from the experimental room to the regular classroom. Even when treatment was introduced into the regular class, follow‐up results showed that with time the target behavior approximated pretreatment levels. The results suggest that (a) the combination of instructions and reinforcement is much more effective than either one of these alone, (b) behavior change is specific to the environmental contingencies, and (c) the group reinforcement technique, which is much more easily implemented, was at least as effective as individual reinforcement in the present study.

Resumo não informado pela fonte indexada.