MR-Research in Neurology and Psychiatry, Georg-August University Goettingen, Goettingen, Germany.
Brain Res. 2011 Jan 31;1371:87-99. doi: 10.1016/j.brainres.2010.10.110. Epub 2010 Nov 5.
Facial emotion perception plays a fundamental role in interpersonal social interactions. Images of faces contain visual information at various spatial frequencies. The amygdala has previously been reported to be preferentially responsive to low-spatial frequency (LSF) rather than to high-spatial frequency (HSF) filtered images of faces presented at the center of the visual field. Furthermore, it has been proposed that the amygdala might be especially sensitive to affective stimuli in the periphery. In the present study we investigated the impact of spatial frequency and stimulus eccentricity on face processing in the human amygdala and fusiform gyrus using functional magnetic resonance imaging (fMRI). The spatial frequencies of pictures of fearful faces were filtered to produce images that retained only LSF or HSF information. Facial images were presented either in the left or right visual field at two different eccentricities. In contrast to previous findings, we found that the amygdala responds to LSF and HSF stimuli in a similar manner regardless of the location of the affective stimuli in the visual field. Furthermore, the fusiform gyrus did not show differential responses to spatial frequency filtered images of faces. Our findings argue against the view that LSF information plays a crucial role in the processing of facial expressions in the amygdala and of a higher sensitivity to affective stimuli in the periphery.
面部情绪感知在人际社交互动中起着基本作用。面部的图像包含各种空间频率的视觉信息。先前的研究报告称，杏仁核对低空间频率（LSF）而非高空间频率（HSF）的面孔图像更敏感，这些图像呈现在视野中心。此外，有人提出杏仁核可能对周边的情感刺激特别敏感。在本研究中，我们使用功能磁共振成像（fMRI）研究了空间频率和刺激外偏对人类杏仁核和梭状回处理面孔的影响。使用过滤方法保留了恐惧面孔的图片的 LSF 或 HSF 信息，从而改变了图片的空间频率。面部图像分别在左或右视野中以两种不同的外偏呈现。与先前的发现相反，我们发现杏仁核对外界的 LSF 和 HSF 刺激的反应方式相似，而不受情感刺激在视野中的位置的影响。此外，梭状回对空间频率过滤后的面孔图像没有表现出不同的反应。我们的研究结果表明，LSF 信息在杏仁核对面部表情的处理中以及对外围情感刺激的更高敏感性方面并没有起到关键作用。
