Halgren E, Raij T, Marinkovic K, Jousmäki V, Hari R
INSERM E9926, Marseilles, France, Massachusetts General Hospital Nuclear Magnetic Resonance Center, Harvard Medical School, USA.
Cereb Cortex. 2000 Jan;10(1):69-81. doi: 10.1093/cercor/10.1.69.
Activation in or near the fusiform gyrus was estimated to faces and control stimuli. Activation peaked at 165 ms and was strongest to digitized photographs of human faces, regardless of whether they were presented in color or grayscale, suggesting that face- and color-specific areas are functionally separate. Schematic sketche evoked approximately 30% less activation than did face photographs. Scrambling the locations of facial features reduced the response by approximately 25% in either hemisphere, suggesting that configurational versus analytic processing is not lateralized at this latency. Animal faces evoked approximately 50% less activity, and common objects, animal bodies or sensory controls evoked approximately 80% less activity than human faces. The (small) responses evoked by meaningless control images were stronger when they included surfaces and shading, suggesting that the fusiform gyrus may use these features in constructing its face-specific response. Putative fusiform activation was not significantly related to stimulus repetition, gender or emotional expression. A midline occipital source significantly distinguished between faces and control images as early as 110 ms, but was more sensitive to sensory qualities. This source significantly distinguished happy and sad faces from those with neutral expressions. We conclude that the fusiform gyrus may selectively encode faces at 165 ms, transforming sensory input for further processing.
对梭状回或其附近区域的激活情况进行了评估，以观察其对面部和对照刺激的反应。激活峰值出现在165毫秒，对人脸的数字化照片反应最强，无论照片是彩色还是灰度呈现，这表明面部特定区域和颜色特定区域在功能上是分开的。示意图引发的激活比人脸照片少约30%。打乱面部特征的位置会使任一脑半球的反应减少约25%，这表明在这个潜伏期，构型加工与分析加工没有明显的偏侧化。动物面部引发的活动约少50%，而普通物体、动物身体或感觉对照物引发的活动比人脸少约80%。当无意义对照图像包含表面和阴影时，引发的（较小）反应更强，这表明梭状回可能利用这些特征来构建其对面部的特定反应。假定的梭状回激活与刺激重复、性别或情感表达没有显著关联。一个枕叶中线源早在110毫秒时就能显著区分面部和对照图像，但对感觉特征更敏感。该源能显著区分快乐和悲伤的面部与中性表情的面部。我们得出结论，梭状回可能在165毫秒时选择性地编码面部，转换感觉输入以便进一步处理。
