Kirsch Irving
Department of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA.
Psychol Bull. 2004 Mar;130(2):341-3; discussion 344-5. doi: 10.1037/0033-2909.130.2.341.
Classical conditioning is included as a component in the response expectancy model of placebo responding. Though introspectable when attention is drawn to them, expectancies need not be in awareness while guiding behavior. Most placebo effects are linked to expectancies, and classical conditioning is one factor (but not the only factor) by which these expectancies can be produced and altered. Conditioned placebo effects without expectancies exist but are relatively rare in humans. The adaptive advantage of cognition is increased response flexibility. For it to convey that benefit, however, it must be capable of overriding the influence of simpler automatic processes. Thus, the higher up the phylogenetic scale, the smaller the role of nonconscious conditioning processes and the larger the role of cognition.
经典条件作用被纳入安慰剂反应的反应预期模型中作为一个组成部分。尽管当注意力被吸引到它们身上时是可以内省的，但预期在指导行为时并不一定处于意识层面。大多数安慰剂效应与预期有关，而经典条件作用是产生和改变这些预期的一个因素（但不是唯一因素）。没有预期的条件性安慰剂效应确实存在，但在人类中相对罕见。认知的适应性优势在于增加反应灵活性。然而，为了传递这种益处，它必须能够超越更简单的自动过程的影响。因此，在系统发育等级中越高，无意识条件作用过程的作用越小，认知的作用越大。
