Merckelbach H, Arntz A, de Jong P, Schouten E
Department of Mental Health Sciences, Limburg University, Maastricht, The Netherlands.
Behav Res Ther. 1993 Nov;31(8):775-9. doi: 10.1016/0005-7967(93)90008-i.
In order to test the hypothesis that low levels of endogenous opioids (endorphins) predispose to strong conditioning effects, female Ss (N = 36) were assigned to a placebo group, a low-dose naltrexone group, or a high-dose naltrexone group and then underwent a classical conditioning procedure. This procedure consisted of an acquisition phase in which all Ss received 5 pairings of a CS+ (neutral picture) and a UCS (100 dB white noise). The CS- (neutral picture) was never followed by a UCS. During extinction, Ss received 4 unreinforced presentations of CS+ and CS-. Throughout the experiment, skin conductance responses (SCRs) to the CSs and UCSs were recorded. Acquisition was successful in that CS+ slides elicited stronger SCRs than CS- slides. However, during acquisition, there was no interaction between drug and differential response (CS+ vs CS-). During extinction, there was no overall remaining effect of conditioning. Again, no evidence was found to suggest that (remaining) effects of conditioning were stronger in the naltrexone treated Ss than in the placebo Ss. If anything, the opposite seemed to be true with especially high-dose naltrexone Ss showing relatively weak conditioning effects.
为了检验内源性阿片类物质（内啡肽）水平低易导致强烈条件作用效应这一假设，将36名女性被试分配到安慰剂组、低剂量纳曲酮组或高剂量纳曲酮组，然后让她们接受经典条件作用程序。该程序包括一个习得阶段，在此阶段所有被试接受5次条件刺激（中性图片）与无条件刺激（100分贝白噪声）的配对。条件刺激-（中性图片）之后从不跟随无条件刺激。在消退阶段，被试接受4次条件刺激+和条件刺激-的无强化呈现。在整个实验过程中，记录对条件刺激和无条件刺激的皮肤电反应（SCR）。习得阶段成功完成，因为条件刺激+幻灯片比条件刺激-幻灯片引发更强的皮肤电反应。然而，在习得阶段，药物与差异反应（条件刺激+与条件刺激-）之间没有交互作用。在消退阶段，没有发现条件作用的总体残留效应。同样，没有证据表明纳曲酮治疗的被试中条件作用的（残留）效应比安慰剂组被试更强。如果有什么不同的话，情况似乎相反，尤其是高剂量纳曲酮组被试表现出相对较弱的条件作用效应。
