Bauch Eva M, Rausch Vanessa H, Bunzeck Nico
Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
Hum Brain Mapp. 2014 Sep;35(9):4594-606. doi: 10.1002/hbm.22497. Epub 2014 Mar 12.
The ability to encode information into long-term memory is not a passive process but can be influenced by motivational factors. While the mesolimbic system has long been associated with reward-driven memory enhancement, the precise neurobiology of processing aversive events and their effects on declarative learning remain unclear. To address this issue, human subjects encoded a series of scene images, which was combined with cues predicting an aversive electric shock with different probabilities (0.2, 0.5, 0.8). Subsequently, recognition memory for the scenes was tested using a remember/know procedure. In a behavioral experiment, shock probability had linear effects on familiarity and inverted u-shaped effects on recollection. While the behavioral effect was absent in experiment 2 (fMRI), at the neural level encoding-related activity in the hippocampus mimicked the recollection specific quadratic effect, whereas activity in the anterior parahippocampal gyrus mirrored the familiarity specific linear relationship that was evident in experiment 1. Importantly, the probability of upcoming shocks was linearly coded in the substantia nigra / ventral tegmental area, and pain associated brain regions, such as the insula, responded to shock delivery. Our results demonstrate that anticipating primary aversive events recruits the human mesolimbic system and differentially modulates declarative memory functions via medial temporal lobe structures.
将信息编码到长期记忆中的能力并非一个被动过程，而是会受到动机因素的影响。虽然中脑边缘系统长期以来一直与奖励驱动的记忆增强相关，但处理厌恶事件及其对陈述性学习影响的精确神经生物学机制仍不清楚。为了解决这个问题，人类受试者对一系列场景图像进行编码，这些图像与预测不同概率（0.2、0.5、0.8）厌恶电击的线索相结合。随后，使用“记得/知道”程序测试对这些场景的识别记忆。在一项行为实验中，电击概率对熟悉度有线性影响，对回忆有倒U形影响。虽然在实验2（功能磁共振成像）中没有观察到行为效应，但在神经层面，海马体中与编码相关的活动模拟了回忆特有的二次效应，而海马旁回前部的活动反映了在实验1中明显的熟悉度特有的线性关系。重要的是，即将到来的电击概率在黑质/腹侧被盖区呈线性编码，并且与疼痛相关的脑区，如脑岛，对电击传递有反应。我们的结果表明，预期主要厌恶事件会激活人类中脑边缘系统，并通过内侧颞叶结构差异调节陈述性记忆功能。
