Department of Biological and Clinical Psychology, University of Greifswald, Greifswald, Germany.
PLoS One. 2013 Sep 5;8(9):e68212. doi: 10.1371/journal.pone.0068212. eCollection 2013.
Recent animal and human research indicates that stress around the time of encoding enhances long-term memory for emotionally arousing events but neural evidence remains unclear. In the present study we used the ERP old/new effect to investigate brain dynamics underlying the long-term effects of acute pre-encoding stress on memory for emotional and neutral scenes. Participants were exposed either to the Socially Evaluated Cold Pressure Test (SECPT) or a warm water control procedure before viewing 30 unpleasant, 30 neutral and 30 pleasant pictures. Two weeks after encoding, recognition memory was tested using 90 old and 90 new pictures. Emotional pictures were better recognized than neutral pictures in both groups and related to an enhanced centro-parietal ERP old/new difference (400-800 ms) during recognition, which suggests better recollection. Most interestingly, pre-encoding stress exposure specifically increased the ERP old/new-effect for emotional (unpleasant) pictures, but not for neutral pictures. These enhanced ERP/old new differences for emotional (unpleasant) scenes were particularly pronounced for those participants who reported high levels of stress during the SECPT. The results suggest that acute pre-encoding stress specifically strengthens brain signals of emotional memories, substantiating a facilitating role of stress on memory for emotional scenes.
最近的动物和人类研究表明，在编码时的压力会增强对情绪激动事件的长期记忆，但神经证据仍不清楚。在本研究中，我们使用 ERP 新旧效应来研究急性预编码应激对情绪和中性场景记忆的长期影响的大脑动力学。参与者在观看 30 张不愉快、30 张中性和 30 张愉快的图片之前，要么接受社会评价性冷压测试（SECPT），要么接受温水对照程序。在编码两周后，使用 90 张旧图片和 90 张新图片进行识别记忆测试。在两组中，情绪图片的识别都好于中性图片，并且与识别过程中增强的中央顶叶 ERP 新旧差异（400-800 毫秒）相关，这表明回忆更好。最有趣的是，预编码应激暴露特别增加了情绪（不愉快）图片的 ERP 新旧效应，但对中性图片没有影响。对于那些在 SECPT 期间报告压力水平较高的参与者，情绪（不愉快）场景的这些增强的 ERP/旧新差异更为明显。研究结果表明，急性预编码应激特别增强了情绪记忆的大脑信号，证实了应激对情绪场景记忆的促进作用。
