Epstein C M, Zangaladze A
Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.
J Clin Neurophysiol. 1996 May;13(3):242-6. doi: 10.1097/00004691-199605000-00008.
We used magnetic brain stimulation with a butterfly coil over the occipital lobes to study extrafoveal visual field effects in six subjects. The visual test pattern was a grid of asterisks around a central fixation point, and the target was the disappearance of one asterisk for a single frame of the video monitor. Using single magnetic pulses at stimulator outputs of 55-95%, we noted robust interference effects at latencies < or = 100 ms, peaking at approximately 50-90 ms. Suppression of visual perception occurred with both transverse and sagittal alignments of the coil. When the coil was moved laterally over either occipital lobe, perception of target disappearance was consistently suppressed in the contralateral visual field. Movement of the coil rostrally produced consistent suppression in the lower and middle field, but preferential suppression of the upper field could not be obtained. This altitudinal asymmetry may be correlated with the anatomy of the occipital lobe in relation to the scalp surface.
我们使用蝶形线圈在枕叶进行磁脑刺激，以研究6名受试者的中央凹外视野效应。视觉测试图案是围绕中央固定点的星号网格，目标是视频监视器单帧中一个星号的消失。在刺激器输出为55 - 95%时使用单个磁脉冲，我们注意到在潜伏期≤100毫秒时存在强烈的干扰效应，在大约50 - 90毫秒时达到峰值。线圈横向和矢状排列时均会出现视觉感知抑制。当线圈在任一枕叶上横向移动时，对侧视野中目标消失的感知会持续受到抑制。线圈向前移动时，在下半视野和中间视野会产生持续抑制，但无法获得对上半视野的优先抑制。这种高度不对称可能与枕叶相对于头皮表面的解剖结构有关。
