Kansei Fukushi Research Institute, Tohoku Fukushi University, Sendai, Japan; Center for Advanced Research for Logic and Sensibility, Keio University, Tokyo, Japan.
Brain Res. 2011 May 16;1390:118-25. doi: 10.1016/j.brainres.2011.03.049. Epub 2011 Apr 13.
Previous studies on laterality in face processing have indicated superiority of the right hemisphere in discriminating and recognizing faces; however, the reasons for this feature are poorly understood. We employed functional MRI (fMRI) to elucidate the origin of this feature and used a paired-stimulus paradigm in which face pairs were presented unilaterally at the left or right visual hemifield of the participants. Each face in a pair was at a different position in the visual field. Refractory suppression in the fMRI response was observed bilaterally at the fusiform face area (FFA) for the same face pairs when pictures were presented in the left visual hemifield. In contrast, suppression was observed bilaterally at the FFA for the different as well as for the same face pairs when pictures were presented in the right visual hemifield. This pattern indicated inferior discrimination ability for paired stimuli presented to the right visual hemifield. These observations, along with changes in bilaterally interlocked responses at the FFA, suggest that low-level visual areas, and not high-level face areas, are strongly associated with the superiority of the right hemisphere in face processing.
先前有关面孔加工偏侧性的研究表明，右半球在辨别和识别面孔方面具有优势；然而，其原因尚不清楚。我们采用功能磁共振成像（fMRI）来阐明这一特征的起源，并使用了一种成对刺激范式，其中面孔对在参与者的左侧或右侧视野中单侧呈现。每对中的一张面孔在视野中的不同位置。当面孔在左侧视野中呈现时，双侧梭状回面孔区（FFA）对相同的面孔对呈现出 fMRI 反应的抑制性后放电。相比之下，当面孔在右侧视野中呈现时，双侧 FFA 对不同和相同的面孔对均呈现出抑制性后放电。这种模式表明，当刺激呈现在右侧视野时，对成对刺激的辨别能力较差。这些观察结果以及 FFA 双侧连锁反应的变化表明，与面孔加工的右半球优势密切相关的是低水平视觉区域，而不是高水平的面孔区域。
