Haist Frank, Lee Kang, Stiles Joan
Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
Front Hum Neurosci. 2010 Oct 8;4:181. doi: 10.3389/fnhum.2010.00181. eCollection 2010.
Controversy surrounds the proposal that specific human cortical regions in the ventral occipitotemporal cortex, commonly called the fusiform face area (FFA) and occipital face area (OFA), are specialized for face processing. Here, we present findings from an fMRI study of identity discrimination of faces and objects that demonstrates the FFA and OFA are equally responsive to processing stimuli at the level of individuals (i.e., individuation), be they human faces or non-face objects. The FFA and OFA were defined via a passive viewing task as regions that produced greater activation to faces relative to non-face stimuli within the middle fusiform gyrus and inferior occipital gyrus. In the individuation task, participants judged whether sequentially presented images of faces, diverse objects, or wristwatches depicted the identical or a different exemplar. All three stimulus types produced equivalent BOLD activation within the FFA and OFA; that is, there was no face-specific or face-preferential processing. Critically, individuation processing did not eliminate an object superiority effect relative to faces within a region more closely linked to object processing in the lateral occipital complex (LOC), suggesting that individuation processes are reasonably specific to the FFA and OFA. Taken together, these findings challenge the prevailing view that the FFA and OFA are face-specific processing regions, demonstrating instead that they function to individuate - i.e., identify specific individuals - within a category. These findings have significant implications for understanding the function of brain regions widely believed to play an important role in social cognition.
关于腹侧枕颞叶皮层中特定的人类皮层区域(通常称为梭状面孔区(FFA)和枕叶面孔区(OFA))专门用于面孔处理的提议存在争议。在此,我们展示了一项关于面孔和物体身份识别的功能磁共振成像(fMRI)研究结果,该研究表明FFA和OFA在个体层面(即个体化)对处理刺激的反应是相同的,无论这些刺激是人脸还是非人脸物体。FFA和OFA是通过一项被动观看任务定义的,即相对于梭状回中部和枕下回中的非面孔刺激,对面孔产生更大激活的区域。在个体化任务中,参与者判断依次呈现的面孔、各种物体或手表的图像描绘的是相同还是不同的示例。所有三种刺激类型在FFA和OFA中产生了等效的血氧水平依赖(BOLD)激活;也就是说,不存在面孔特异性或面孔优先处理。至关重要的是,相对于枕外侧复合体(LOC)中与物体处理联系更紧密的区域内的面孔,个体化处理并没有消除物体优势效应,这表明个体化过程在FFA和OFA中具有相当的特异性。综上所述,这些发现挑战了FFA和OFA是面孔特异性处理区域的主流观点,相反,表明它们的功能是在一个类别中区分个体——即识别特定个体。这些发现对于理解广泛认为在社会认知中起重要作用的脑区功能具有重要意义。