Morris Richard W, Bouton Mark E
Department of Psychology, University of Vermont, Burlington, VT 05401, USA.
J Exp Psychol Anim Behav Process. 2006 Oct;32(4):371-85. doi: 10.1037/0097-7403.32.4.371.
Although unconditioned stimulus (US) magnitude influences conditioning, no experiment has addressed whether it influences a decision point at which the organism first responds (Gallistel & Gibbon, 2000). Two appetitive conditioning experiments with rats confirmed that the rate of food cup entries and proportion of head jerking were related to the number of pellets (US) provided after the conditioned stimulus. In addition, the onset of responding measured by the number of reinforcers to a criterion or by a quantitatively identified change point also reflected US magnitude. Two aversive conditioning experiments also found that the amount and onset of freezing were related to footshock intensity. All experiments identified a trial at which responding increased abruptly in individual subjects. However, the point where the increase occurred was earlier with larger USs.
尽管无条件刺激（US）的强度会影响条件作用，但尚无实验探讨它是否会影响生物体首次做出反应的决策点（加利斯泰尔和吉本，2000）。两项对大鼠进行的食欲性条件作用实验证实，进入食杯的速率和头部抽搐的比例与条件刺激后提供的食丸数量（无条件刺激）有关。此外，通过达到标准的强化物数量或通过定量确定的变化点来衡量的反应起始点也反映了无条件刺激的强度。两项厌恶性条件作用实验还发现，僵住的程度和起始点与足部电击强度有关。所有实验都确定了单个受试者反应突然增加的一次试验。然而，无条件刺激越大，增加出现的点就越早。
