Studies on visual perception mechanism using magnetoenc ephalography

我们用脑磁图研究了个体间纹外区对视觉运动反应的位置差异。从12名受试者的右颞枕区的视觉运动发作的磁反应记录。所有受试者对明显的或随机的点相干运动都有明确的反应。这些响应的起源进行了研究，通过使用单一的等效电流偶极子模型。还确定了每个受试者离原点最近的头皮，这在经颅刺激研究中可能有用。虽然所有受试者的磁响应应该具有相同的功能特性;与专门同步到运动开始的神经活动有关，但受试者之间的估计起源差异很大。起源的位置可以分为三种类型之一：颞枕，枕，或顶骨，根据个人的三维磁共振图像中的脑沟解剖研究。颞枕叶类型被发现的7个科目，和解剖学的区域周围的人类MT/V5。2例受试者为枕叶型，其区域位于解剖学MT/V5后方，在解剖学上对应于V3 A。其他3例受试者的起源被归类为解剖MT/V5的顶叶型背吻侧，区域位于上级颞沟后端周围。虽然所有这些皮层区域似乎都与视觉运动的神经过程有关，但现在必须确定它们在功能上是否对应于相同的名称或迁移的MT/V5。

We used magnetoencephalography to study inter-individual locational difference in the extrastriate region which responds to visual motion. Magnetic responses to visual motion onset from the right temporo-occipital area were recorded from 12 subjects. All the subjects had clear responses to apparent or random dot coherent motion. The origins of these responses was investigated by use of the single equivalent current dipole model. The nearest scalp to the origin also was identified for each subject, which may be useful in transcranial stimulation studies. Although the magnetic responses of all the subjects should have the same functional properties ; be related to neural activities synchronized exclusively to the onset of motion, the estimated origins varied greatly among the subjects. The location of origin could be classified as one of three types : temporo-occipital, occipital, or parietal, according to the sulcal anatomy investigated in the individual's three-dimensional magnetic resonance image. Temporo-occipital types were found for seven subjects, and anatomically the regions were around human MT/V5. Two subjects had the occipital type, with regions posterior to the anatomical MT/V5 and corresponding to V3A anatomically. The other three subjects had origins classified as the parietal type dorso-rostral to the anatomical MT/V5, with regions around the posterior end of the superior temporal sulcus. Although all these cortical regions appear to be related to the neural process of visual motion, whether they correspond functionally to the same names or migrated MT/V5 must now be determined.