Hartogsveld Bart, van Ruitenbeek Peter, Quaedflieg Conny W E M, Smeets Tom
Department of Clinical Psychological Science, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Department of Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Exp Psychol. 2020 Mar;67(2):99-111. doi: 10.1027/1618-3169/a000485.
Instrumental learning is regulated by two memory systems: a relatively rigid but efficient habit system and a flexible but resource-demanding goal-directed system. Previous work has demonstrated that exposure to acute stress may shift the balance between these systems toward the habitual system. In the current study, we used a 2-day outcome devaluation paradigm with a 75% reward contingency rate and altered food reward categories to replicate and extend our previous findings. Participants learned neutral stimulus-response-reward associations on the first day. On the second day, rewards were devalued by eating to satiety. Subsequently, acute stress was induced in half of the participants using the Maastricht Acute Stress Test, while the other half engaged in a nonstressful control task. Finally, relative goal-directed versus habitual behavior was evaluated in a slips-of-action phase, where more slips-of-action indicate a shift toward the habitual system. Results showed that participants successfully acquired the stimulus-response-reward associations, that devaluation was effective, and that stressed participants displayed significant increases in cortisol and blood pressure. Stress led participants to commit more slips-of-action compared with nonstressed controls. The current study extends previous work, showing that the employed paradigm and outcome devaluation procedure are boundary conditions to the stress-induced shift in instrumental responding.
一种相对刻板但高效的习惯系统和一种灵活但资源需求高的目标导向系统。先前的研究表明，暴露于急性应激可能会使这些系统之间的平衡向习惯系统倾斜。在当前的研究中，我们采用了一种为期2天的结果贬值范式，奖励概率为75%，并改变食物奖励类别，以复制和扩展我们之前的研究结果。参与者在第一天学习中性刺激-反应-奖励关联。第二天，通过进食至饱腹感来降低奖励价值。随后，使用马斯特里赫特急性应激测试对一半参与者施加急性应激，而另一半参与者进行无压力的对照任务。最后，在一个行动失误阶段评估相对目标导向行为与习惯行为，行动失误越多表明向习惯系统的转变。结果表明，参与者成功习得刺激-反应-奖励关联，贬值有效，且受应激的参与者皮质醇和血压显著升高。与无应激对照组相比，应激导致参与者出现更多行动失误。当前的研究扩展了先前的工作，表明所采用的范式和结果贬值程序是应激诱导工具性反应转变的边界条件。
