Department of Cognitive Psychology, Ruhr-University Bochum, Bochum, Germany.
Psychoneuroendocrinology. 2010 Aug;35(7):977-86. doi: 10.1016/j.psyneuen.2009.12.010. Epub 2010 Jan 13.
Instrumental action can be controlled by two anatomically and functionally distinct systems: a goal-directed system that learns action-outcome associations and a habit system that learns stimulus-response associations without any link to the incentive value of the outcome. Recent evidence indicates that stress before learning modulates these two systems in favor of habitual control. Here, we examined the impact of a stress exposure after learning on instrumental performance. Participants learned to choose two instrumental actions that were associated with the delivery of different food rewards. After learning, one of these food rewards was devalued as participants were saturated with that food. Before being re-exposed to the instrumental actions in extinction, participants were subjected to the socially evaluated cold pressor test or a control procedure. Controls but not stressed participants reduced responding to the action associated with the devalued outcome. That is, acute stress before extinction testing abolished sensitivity of performance to outcome devaluation. Cortisol responses to stress correlated significantly with habitual performance. These findings show that stress induced by the socially evaluated cold pressor test can make behavior habitual without affecting processes involved in learning.
一个是有目标导向的系统，它学习动作-结果的关联；另一个是习惯系统，它学习刺激-反应的关联，而与结果的激励价值无关。最近的证据表明，学习前的压力会调节这两个系统，使其有利于习惯控制。在这里，我们研究了学习后压力暴露对工具性行为的影响。参与者学习选择两种与不同食物奖励相关的工具性动作。学习后，其中一种食物奖励被贬值，因为参与者被这种食物饱和了。在重新暴露于消退中的工具性行为之前，参与者接受了社会评价的冷水压迫测试或对照程序。对照组但不是应激组的参与者减少了对与贬值结果相关的动作的反应。也就是说，在进行消退测试之前的急性应激消除了对结果贬值的行为敏感性。皮质醇对压力的反应与习惯性表现显著相关。这些发现表明，社会评价的冷水压迫测试引起的应激可以使行为习惯化，而不影响学习过程。
