Face processing occurs outside the fusiform 'face area' in autism:: evidence from functional MRI
Face processing occurs outside the fusiform 'face area' in autism:: evidence from functional MRI
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DOI：
10.1093/brain/124.10.2059
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发表时间：
2001-10-01
期刊：
影响因子：
14.5
通讯作者：
Courchesne, E
中科院分区：
文献类型：
--
作者：
Pierce, K;Müller, RA;Courchesne, E
处理人脸是大多数社交互动的焦点，但对于自闭症患者来说，这一简单的感知任务是困难的，因为自闭症患者通常只花有限的时间进行面对面的眼神交流或社交活动。因此，研究自闭症患者的面孔加工不仅重要，因为它可能是理解这种障碍的社会缺陷所不可或缺的，而且还因为它提供了一个独特的机会来研究与正常面孔加工的功能专门化相关的经验性因素。简而言之，自闭症可能是仅有的几种疾病之一，受影响的人从出生起就会减少进行面部处理的时间。使用功能磁共振成像，比较了自闭症患者和正常对照受试者在面孔知觉任务中的血流动力学反应。在非空间归一化图像上手动跟踪四个感兴趣区(ROI)，即梭状回(FG)、颞下回、颞中回和杏仁核，并计算每个受试者的感兴趣区活跃百分比。在Talairach空间也进行了分析。总体结果显示，自闭症患者的FG异常微弱或没有激活，枕下回、颞上沟和杏仁核的激活显著减少。相反，只有自闭症患者的杏仁核存在解剖异常，其平均体积与正常人相比显著减小。两组之间的反应时间和准确度指标没有差异。因此，虽然自闭症受试者可以执行面孔感知任务，但在自闭症受试者中，没有一个支持正常面孔加工的区域显著活跃。相反，在每个自闭症患者中，面对最大激活的异常和个体特有的神经部位(例如额叶皮质、初级视觉皮质等)，这与每个正常受试者在传统梭形面部区域(FFA)内最大激活的100%一致性形成鲜明对比。看来，与正常人相比，自闭症患者使用不同的神经系统来“看”脸，每个患者都通过一个独特的神经回路来实现这一点。自闭症患者中看到的这种特定于个人的、分散的激活模式与正常人中看到的高度一致的FG激活形成对比，这表明经验因素确实在FFA的正常发展中发挥了作用。
Processing the human face is at the focal point of most social interactions, yet this simple perceptual task is difficult for individuals with autism, a population that spends limited amounts of time engaged in face-to-face eye contact or social interactions in general. Thus, the study of face processing in autism is not only important because it may be integral to understanding the social deficits of this disorder, but also, because it provides a unique opportunity to study experiential factors related to the functional specialization of normal face processing. In short, autism may be one of the only disorders where affected individuals spend reduced amounts of time engaged in face processing from birth. Using functional MRI, haemodynamic responses during a face perception task were compared between adults with autism and normal control subjects. Four regions of interest (ROIs), the fusiform gyrus (FG), inferior temporal gyrus, middle temporal gyrus and amygdala were manually traced on non-spatially normalized images and the percentage ROI active was calculated for each subject. Analyses in Talairach space were also performed. Overall results revealed either abnormally weak or no activation in FG in autistic patients, as well as significantly reduced activation in the inferior occipital gyrus, superior temporal sulcus and amygdala. Anatomical abnormalities, in contrast, were present only in the amygdala in autistic patients, whose mean volume was significantly reduced as compared with normals. Reaction time and accuracy measures were not different between groups. Thus, while autistic subjects could perform the face perception task, none of the regions supporting face processing in normals were found to be significantly active in the autistic subjects. Instead, in every autistic patient, faces maximally activated aberrant and individual-specific neural sites (e.g. frontal cortex, primary visual cortex, etc.), which was in contrast to the 100% consistency of maximal activation within the traditional fusiform face area (FFA) for every normal subject. It appears that, as compared with normal individuals, autistic individuals 'see' faces utilizing different neural systems, with each patient doing so via a unique neural circuitry. Such a pattern of individual-specific, scattered activation seen in autistic patients in contrast to the highly consistent FG activation seen in normals, suggests that experiential factors do indeed play a role in the normal development of the FFA.