Peyk Peter, Schupp Harald T, Elbert Thomas, Junghöfer Markus
Department of Psychology, University of Basel, Missionsstrasse 60/62, 4055 Basel, Switzerland.
Brain Topogr. 2008 Jun;20(4):205-15. doi: 10.1007/s10548-008-0052-7. Epub 2008 Mar 14.
Recent functional magnetic resonance imaging (fMRI) and event-related brain potential (ERP) studies provide empirical support for the notion that emotional cues guide selective attention. Extending this line of research, whole head magneto-encephalogram (MEG) was measured while participants viewed in separate experimental blocks a continuous stream of either pleasant and neutral or unpleasant and neutral pictures, presented for 330 ms each. Event-related magnetic fields (ERF) were analyzed after intersubject sensor coregistration, complemented by minimum norm estimates (MNE) to explore neural generator sources. Both streams of analysis converge by demonstrating the selective emotion processing in an early (120-170 ms) and a late time interval (220-310 ms). ERF analysis revealed that the polarity of the emotion difference fields was reversed across early and late intervals suggesting distinct patterns of activation in the visual processing stream. Source analysis revealed the amplified processing of emotional pictures in visual processing areas with more pronounced occipito-parieto-temporal activation in the early time interval, and a stronger engagement of more anterior, temporal, regions in the later interval. Confirming previous ERP studies showing facilitated emotion processing, the present data suggest that MEG provides a complementary look at the spread of activation in the visual processing stream.
近期的功能磁共振成像（fMRI）和事件相关脑电位（ERP）研究为情绪线索引导选择性注意这一观点提供了实证支持。为拓展这一研究方向，研究人员在参与者于不同实验模块中观看连续不断的图片时，测量了全脑磁脑电图（MEG）。这些图片分为两类，一类是愉悦与中性图片，另一类是不悦与中性图片，每幅图片呈现330毫秒。在进行受试者间传感器配准后，对事件相关磁场（ERF）进行了分析，并辅以最小范数估计（MNE）以探究神经发生器来源。这两种分析方法均表明，在早期（120 - 170毫秒）和晚期（220 - 310毫秒）存在选择性情绪处理。ERF分析显示，情绪差异场的极性在早期和晚期区间发生了反转，这表明视觉处理流中存在不同的激活模式。源分析显示，在视觉处理区域中，情绪图片的处理得到增强，早期区间枕颞顶叶激活更为明显，而晚期区间则更多地涉及更靠前的颞叶区域。本研究数据证实了先前ERP研究中关于情绪处理得到促进的结果，表明MEG为视觉处理流中激活的传播提供了补充视角。
