McSweeney Frances K, Kowal Benjamin P, Murphy Eric S, Wiediger Roberta S
Department of Psychology, Washington State University, Pullman, WA 99164-4820, USA.
Behav Processes. 2005 Nov 1;70(3):235-46. doi: 10.1016/j.beproc.2005.07.004.
The present experiment examined whether habituation contributes to within-session decreases in operant responding for water reinforcers. The experiment asked if this responding can be dis-habituated, a fundamental property of habituated behavior. During baseline, rats' lever pressing was reinforced by water on a variable interval 15-s schedule. During experimental conditions, rats responded on the same schedule and a new stimulus was introduced for 5 min at 15, 30 or 45 min into the 60-min session. The new stimulus was extinction, continuous reinforcement or flashing lights in different conditions. Rate of responding primarily decreased within the session during baseline. Introducing a new stimulus sometimes suppressed (extinction, continuous reinforcement) and sometimes increased (flashing lights) responding while it was in effect. The new stimulus increased responding after it ended and before it was presented in the session. The results are incompatible with the idea that non-habituation satiety factors (e.g., cellular hydration and blood volume) contributed to within-session changes in responding. These satiety factors should increase with increases in consumption, decrease with decreases in consumption and remain constant with constant consumption of water. Nevertheless, all stimulus changes increased operant responding for water. These results support the idea that habituation contributes to within-session decreases in responding for water reinforcers.
本实验研究了习惯化是否会导致在实验过程中对水强化物的操作性反应减少。该实验探讨了这种反应是否会去习惯化，这是习惯化行为的一个基本特性。在基线期，大鼠按压杠杆以可变间隔15秒的时间表获得水强化。在实验条件下，大鼠按相同时间表做出反应，并在60分钟实验时段的第15、30或45分钟引入新刺激5分钟。在不同条件下，新刺激分别为消退、连续强化或闪烁灯光。在基线期，反应率在实验过程中主要下降。引入新刺激时，有时会抑制（消退、连续强化）反应，有时会增加（闪烁灯光）反应。新刺激结束后且在下次实验时段呈现前会增加反应。这些结果与非习惯化饱足因素（如细胞水合作用和血容量）导致实验过程中反应变化的观点不一致。这些饱足因素应随着饮水量增加而增加，随着饮水量减少而减少，且在水摄入量恒定的情况下保持不变。然而，所有刺激变化都增加了对水的操作性反应。这些结果支持了习惯化导致在实验过程中对水强化物的反应减少这一观点。
