Experimental Psychology, University of Groningen, Groningen, The Netherlands.
Clin Neurophysiol. 2012 Mar;123(3):513-26. doi: 10.1016/j.clinph.2011.07.040. Epub 2011 Sep 1.
The aim was to investigate the effects of spatial attention, stimulus location, and emotional expression on the processing of face stimuli.
Healthy volunteers performed two sustained attention tasks, focusing their attention on either fixation (foveal location) or on a location several degrees above fixation (parafoveal location). Photographs of faces with either a neutral or a fearful expression were presented randomly at one of these locations. Event-related potentials were recorded in response to the face stimuli.
Spatial attention modulated the early P1 and N1 components for both foveally and parafoveally presented stimuli. Emotional expression effects already occurred at the P1 stage in response to attended foveal stimuli, but only arose from 220ms post-stimulus onwards in response to attended parafoveal stimuli. When faces were unattended, emotional expression effects were still present for parafoveal stimuli, whereas they were completely absent for foveal stimuli.
The modulations of the P1/N1 components by fearful faces are due to an early sensory modulation of extrastriate generators, and reflect an enhanced allocation of attention to threat-related stimuli.
Future studies should take into account the possibility that spatial attention effects and effects of emotional expression processing are different for different positions in the visual field.
旨在探讨空间注意、刺激位置和情绪表达对面部刺激加工的影响。
健康志愿者进行了两项持续注意力任务，分别将注意力集中在注视点（中央凹位置）或注视点上方几个度数的位置（周边位置）。以中性或恐惧表情的面孔照片随机呈现于这些位置之一。对面部刺激进行事件相关电位记录。
空间注意调制了中央凹和周边呈现刺激的早期 P1 和 N1 成分。情绪表达的影响在对注视点刺激进行注意时，在 P1 阶段就已经出现，但仅在对注意的周边刺激做出反应时，才从刺激后 220ms 开始出现。当面孔不被注意时，周边刺激仍存在情绪表达效应，而中央凹刺激则完全没有。
恐惧面孔对 P1/N1 成分的调制归因于对枕叶外发生器的早期感觉调制，反映了对与威胁相关刺激的注意力的增强分配。
未来的研究应考虑到空间注意效应和情绪表达处理效应在视野不同位置可能不同的可能性。
