Watson J D, Myers R, Frackowiak R S, Hajnal J V, Woods R P, Mazziotta J C, Shipp S, Zeki S
Department of Anatomy, University College London, United Kingdom.
Cereb Cortex. 1993 Mar-Apr;3(2):79-94. doi: 10.1093/cercor/3.2.79.
In pursuing our work on the organization of human visual cortex, we wanted to specify more accurately the position of the visual motion area (area V5) in relation to the sulcal and gyral pattern of the cerebral cortex. We also wanted to determine the intersubject variation of area V5 in terms of position and extent of blood flow change in it, in response to the same task. We therefore used positron emission tomography (PET) to determine the foci of relative cerebral blood flow increases produced when subjects viewed a moving checkerboard pattern, compared to viewing the same pattern when it was stationary. We coregistered the PET images from each subject with images of the same brain obtained by magnetic resonance imaging, thus relating the position of V5 in all 24 hemispheres examined to the individual gyral configuration of the same brains. This approach also enabled us to examine the extent to which results obtained by pooling the PET data from a small group of individuals (e.g., six), chosen at random, would be representative of a much larger sample in determining the mean location of V5 after transformation into Talairach coordinates. After stereotaxic transformation of each individual brain, we found that the position of area V5 can vary by as much as 27 mm in the left hemisphere and 18 mm in the right for the pixel with the highest significance for blood flow change. There is also an intersubject variability in blood flow change within it in response to the same visual task. V5 nevertheless bears a consistent relationship, within each brain, to the sulcal pattern of the occipital lobe. It is situated ventrolaterally, just posterior to the meeting point of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus. In position it corresponds almost precisely with Flechsig's Feld 16, one of the areas that he found to be myelinated at birth.
在开展关于人类视觉皮层组织的研究工作时，我们希望更精确地确定视觉运动区（V5区）相对于大脑皮层沟回模式的位置。我们还想确定V5区在位置以及血流变化范围方面的个体间差异，这些差异是在受试者执行相同任务时产生的。因此，我们使用正电子发射断层扫描（PET）来确定当受试者观看移动的棋盘图案时，相较于观看静止的相同图案，大脑相对血流增加的焦点位置。我们将每个受试者的PET图像与通过磁共振成像获得的同一大脑的图像进行配准，从而将所检查的全部24个半球中V5区的位置与同一大脑的个体脑回结构联系起来。这种方法还使我们能够检验，在将PET数据汇集自随机选择的一小群个体（例如六人）后所得到的结果，在确定V5区转换为Talairach坐标后的平均位置时，能在多大程度上代表一个大得多的样本。在对每个个体大脑进行立体定向转换后，我们发现，对于血流变化具有最高显著性的像素而言，V5区在左半球的位置变化可达27毫米，在右半球可达18毫米。在执行相同视觉任务时，其内部的血流变化也存在个体间差异。然而，在每个大脑中，V5区与枕叶的沟回模式保持着一致的关系。它位于腹外侧，恰好在颞下沟升支与枕外侧沟交汇点的后方。在位置上，它几乎与Flechsig的16区精确对应，Flechsig发现该区域在出生时就已髓鞘化。
