J Exp Anal Behav. 1973 Mar;19(2):211-8. doi: 10.1901/jeab.1973.19-211.
Four pigeons were trained to avoid shock by pecking a key on a free-operant avoidance schedule in which no exteroceptive stimulus signalled impending shock. Response rate was an inverse function of response-shock interval when shock-shock interval was held constant at 2 sec and response-shock intervals varied from 5 to 40 sec. Amphetamine increased response rates in two subjects and reserpine markedly reduced responding in one.
四只鸽子通过在自由操作回避程序中啄键来避免受到电击,该程序中没有外感受性刺激来提示即将到来的电击。当电击-电击间隔保持在 2 秒不变,而反应-电击间隔从 5 秒变化到 40 秒时,反应率是反应-电击间隔的反函数。安非他命在两个被试中增加了反应率,利血平则显著降低了一个被试的反应。