Abstract
[Nature of the Operant and Differential Reinforcement of Low Rates in the Pigeon]
Pigeons were conditioned in a multiple, two-operants drl schedule of reinforcement. The response delay required was 10 seconds. The operants used were key-pecking and treadle-pressing, each being associated wiih a coloured stimulus, and reinforced by grain presentation. After a 12-session baseline the subjects were shifted to a chain schedule in which the key-pecks were reinforced by appearance of a conditioned stimulus, the other response remaining reinforced by grain. After a return to baseline conditions the subjects were submitted to the reverse chain schedule, i.e. with the treadle press being reinforced hy a conditioned stimulus. Then the subjects were finally returned to baseline conditions. Important lengthening ot tnterresponse times, together with increase of the percent reinforced responses were observed for each operant when conditioned stimulus instead of grain was the reinforcement. These effects were less marked and there was more day-to-day variability in the case of the treadle-press response. The results are discussed with regards to the problem of the nature of operants, that is. the more or less arbitrary relationship between the behavior unit and its reinforcing consequences.