Siegle Greg J, Steinhauer Stuart R, Thase Michael E, Stenger V Andrew, Carter Cameron S
University of Pittsburgh Medical School and Department of Veterans Affairs Medical Center, Pittsburgh, Pennsylvania, USA.
Biol Psychiatry. 2002 May 1;51(9):693-707. doi: 10.1016/s0006-3223(02)01314-8.
Previous research suggests that depressed individuals engage in prolonged elaborative processing of emotional information. A computational neural network model of emotional information processing suggests this process involves sustained amygdala activity in response to processing negative features of information. This study examined whether brain activity in response to emotional stimuli was sustained in depressed individuals, even following subsequent distracting stimuli.
Seven depressed and 10 never-depressed individuals were studied using event-related functional magnetic resonance imaging during alternating 15-sec emotional processing (valence identification) and non-emotional processing (Sternberg memory) trials. Amygdala regions were traced on high-resolution structural scans and co-registered to the functional data. The time course of activity in these areas during emotional and non-emotional processing trials was examined.
During emotional processing trials, never-depressed individuals displayed amygdalar responses to all stimuli, which decayed within 10 sec. In contrast, depressed individuals displayed sustained amygdala responses to negative words that lasted throughout the following non-emotional processing trials (25 sec later). The difference in sustained amygdala activity to negative and positive words was moderately related to self-reported rumination.
Results suggest that depression is associated with sustained activity in brain areas responsible for coding emotional features.
先前的研究表明，抑郁个体对情绪信息进行长时间的精细加工。一个情绪信息处理的计算神经网络模型表明，这一过程涉及杏仁核持续活动，以应对信息负面特征的处理。本研究考察了即使在随后出现干扰性刺激的情况下，抑郁个体对情绪刺激的脑活动是否持续。
使用事件相关功能磁共振成像对7名抑郁个体和10名从未抑郁的个体进行研究，期间交替进行15秒的情绪处理（效价识别）和非情绪处理（斯特恩伯格记忆）试验。在高分辨率结构扫描上追踪杏仁核区域，并将其与功能数据进行配准。研究了这些区域在情绪和非情绪处理试验期间的活动时间进程。
在情绪处理试验期间，从未抑郁的个体对所有刺激均表现出杏仁核反应，且在10秒内衰减。相比之下，抑郁个体对负面词汇表现出持续的杏仁核反应，这种反应在随后的非情绪处理试验（25秒后）中一直持续。杏仁核对负面和正面词汇持续活动的差异与自我报告的沉思有中度相关性。
结果表明，抑郁症与负责编码情绪特征的脑区持续活动有关。
