Weatherly J N, Stout J E, McMurry A S, Rue H C, Melville C L
Department of Psychology, McNeese State University, Lake Charles, LA 70609-1895, USA.
Behav Processes. 1999 Jul;46(3):227-43. doi: 10.1016/s0376-6357(99)00046-7.
The present study investigated whether within-session responding was specific to the reinforcer currently being delivered and whether it was determined solely by retrospective factors. In four separate experiments, four rats pressed a lever on a multiple variable interval 60-s variable interval 60-s schedule during 60-min sessions. A different reinforcer (5% liquid sucrose or food pellets) was delivered in each half of the session. Rate of reinforcement in one half of the session varied across conditions. Response patterns in the second half of the session were unaffected by changes in the conditions of reinforcement of the other reinforcer in the first half of the session (specificity). Rate of responding was affected, however. The upcoming reinforcer influenced responding when sucrose was delivered in the first half of the session and food pellets were delivered in the second half, but not when their order was reversed. This effect makes contact with several other areas of research (e.g. behavioral contrast). They also suggest that the leading explanations for within-session changes in responding may be limited or incomplete.
本研究调查了时段内反应是否特定于当前正在提供的强化物，以及它是否仅由回顾性因素决定。在四个独立的实验中，四只大鼠在60分钟的时段内按照多重可变间隔60秒-可变间隔60秒的时间表按压杠杆。在每个时段的前半段和后半段分别给予不同的强化物（5%的液体蔗糖或食丸）。在每个时段的前半段，强化率在不同条件下有所变化。时段后半段的反应模式不受时段前半段另一种强化物强化条件变化的影响（特异性）。然而，反应率受到了影响。当蔗糖在时段前半段给予而食丸在时段后半段给予时，即将到来的强化物会影响反应，但当它们的顺序颠倒时则不会。这种效应与其他几个研究领域（如行为对比）相关。它们还表明，对时段内反应变化的主要解释可能是有限的或不完整的。
