Schedule sensitivity of instructed human operant behaviour: Effects of warning and of social stimuli with elaborate and minimal instructions.

Abstract

Schedule insensitivity of behaviours that are established through elaborate instructions is a frequently reported finding in the behavioural literature. This insensitivity usually takes one of two forms: (a) behaviour pattern that is not appropriate to the schedule in effect or (b) failure of the behaviour pattern to adjust once a new unannounced schedule is put in effect. However, a number of methodological flaws in previously published studies hinder a clear interpretation of these findings. The current series of studies attempted to rectify these problems by including sufficiently large groups of subjects (n = 14 or 15) to allow for acceptable levels of power. In addition, the same experimental task was used throughout to provide continuity. This task involved first establishing steady-state responding on a multiple DRL6s/FR18 schedule, and then changing the parameters of the schedule, without alerting subjects to this change. Experiment 1 attempted to replicate the previous findings that indicated that elaborate instructions induced schedule insensitivity when the multiple schedule was changed to EXT/EXT. Experiment 2 investigated the generalisability of the findings of Experiment 1 by examining the effect of a change in contingency to FR18/FR18. Experiments 3 and 4 investigated whether the findings of the first two studies were due to the effect of a "social variable" (the salience of the social stimuli). Experiments 1, 2, and 3 also investigated the effect of a "warning" that conditions may change at any tune. Overall, the results suggest that the warning decreases the schedule insensitivity engendered by the elaborate instructions. The results also suggest that the salience of the social stimuli is an important factor in producing the "insensitivity effect," and may be responsible for some of the more dramatic results in the literature. Further, the findings raise the question of whether instructions do, in fact, engender schedule insensitivity.