Humboldt-Universität zu Berlin, Germany.
Neuroimage. 2015 Jul 1;114:147-57. doi: 10.1016/j.neuroimage.2015.03.063. Epub 2015 Apr 1.
Affective stimuli such as emotional words, scenes or facial expressions elicit well-investigated emotional responses. For instance, two distinct event-related brain potentials (ERPs) have been reported in response to emotional facial expressions, the early posterior negativity (EPN), associated with enhanced attention and perception of affective stimuli, and a later centro-parietal positivity (LPP) that is taken to reflect evaluations of the intrinsic relevance of emotional stimuli. However, other rich sources of emotions that have as yet received little attention are internal mental events such as thoughts, memories and imagination. Here we investigated mental imagery of emotional facial expressions and its time course using ERPs. Participants viewed neutral familiar and unfamiliar faces, and were subsequently asked to imagine the faces with an emotional or neutral expression. Imagery was compared to visually perceiving the same faces with the different expressions. Early ERP modulations during imagery resemble the effects frequently reported for perceived emotional facial expressions, suggesting that common early processes are associated with emotion perception and imagination. A later posterior positivity was also found in the imagery condition, but with a different distribution than for perception. These findings underscore the similarity of the brain's responses to internally generated and external sources of emotions.
情感刺激，如情绪词、场景或面部表情，会引起经过充分研究的情感反应。例如，人们已经发现了两种与情绪面部表情相关的独特事件相关脑电位（ERP），即早期后负波（EPN），它与增强的注意力和对情感刺激的感知有关，以及稍后的中央顶叶正波（LPP），它被认为反映了对情感刺激内在相关性的评估。然而，其他丰富的情绪来源，如思想、记忆和想象，迄今为止还没有受到太多关注。在这里，我们使用 ERP 研究了情绪面部表情的心理意象及其时间过程。参与者观看了中性熟悉和不熟悉的面孔，然后被要求想象这些面孔带有情绪或中性表情。将想象与以不同表情视觉感知相同的面孔进行比较。想象过程中的早期 ERP 调制类似于经常报道的感知情绪面部表情的效果，这表明与情绪感知和想象相关的常见早期过程是相似的。在想象条件下也发现了一个后期后正波，但分布与感知不同。这些发现强调了大脑对内部产生的和外部的情绪源的反应的相似性。
