Dreifus Laura, Engler Harald, Kissler Johanna
Department of Psychology, University of Konstanz, 78457 Konstanz, Germany.
Institute of Medical Psychology and Behavioral Immunobiology, University Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany.
Neurobiol Learn Mem. 2014 Apr;110:35-46. doi: 10.1016/j.nlm.2014.01.010. Epub 2014 Jan 29.
Retrieval-induced forgetting (RIF) is the phenomenon that 'retrieval-practice', the repeated retrieval of a subset of initially learned material, can impair the recall of episodically related memories. Previous studies showed that RIF is eliminated when retrieval-practice is carried out under psycho-social stress, anxiety, or in negative mood. However, pharmacological manipulation by hydrocortisone did not eliminate the effect. This study investigated the effect of beta-adrenergic blockade on stress-induced modulations of RIF, addressing possible interactive effects of the glucocorticoid and sympatho-adrenomedullary systems. Participants learned categorized word lists and then received either 60 mg propranolol or a placebo. After 90 min they were exposed to the TSST. A third group did not receive any medication and performed a non-stressful control task with the same timing as the other two groups. Finally, all participants underwent retrieval-practice and final recall. Both TSST groups exhibited a stress-induced increase in cortisol-levels, and the placebo group also exhibited large increases in markers of sympathetic nervous system activity and more psychological distress at the time of retrieval-practice. Although, overall recall was poorer under stress, an overall RIF effect emerged irrespective of group and showed no clear modulation by stress with or without beta-adrenergic blockade. In previous demonstrations of RIF elimination by negative emotion, state induction and retrieval-practice followed very briefly after initial learning. Given that both the previous study of hydrocortisone effects on RIF and the present study used longer delays between learning and retrieval-practice, the possibility that stress effects on retrieval-practice eliminate RIF only relatively briefly after learning is discussed.
提取诱发遗忘（RIF）是一种现象，即对最初所学材料的一个子集进行重复提取的“提取练习”会损害对情节相关记忆的回忆。先前的研究表明，当在心理社会压力、焦虑或消极情绪下进行提取练习时，提取诱发遗忘会被消除。然而，氢化可的松的药物操作并没有消除这种效应。本研究调查了β-肾上腺素能阻断对应激诱导的提取诱发遗忘调节的影响，探讨了糖皮质激素和交感-肾上腺髓质系统可能的交互作用。参与者学习分类单词列表，然后接受60毫克普萘洛尔或安慰剂。90分钟后，他们接受了TSST（Trier社会应激测试）。第三组没有接受任何药物治疗，而是在与其他两组相同的时间进行了一项无压力的对照任务。最后，所有参与者都进行了提取练习和最终回忆。两个TSST组都表现出应激诱导的皮质醇水平升高，安慰剂组在提取练习时交感神经系统活动标志物也大幅增加，且心理困扰更多。尽管在应激状态下总体回忆较差，但无论组别如何，都出现了总体的提取诱发遗忘效应，并且在有或没有β-肾上腺素能阻断的情况下，应激均未表现出明显的调节作用。在先前关于消极情绪消除提取诱发遗忘的演示中，状态诱导和提取练习在初始学习后很快就进行了。鉴于先前关于氢化可的松对提取诱发遗忘影响的研究以及本研究在学习和提取练习之间都使用了更长的延迟时间，因此讨论了应激对提取练习的影响仅在学习后相对较短时间内消除提取诱发遗忘的可能性。
