Vanni S, Raninen A, Näsänen R, Tanskanen T, Hyvärinen L
Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, Espoo.
Neuroreport. 2001 Mar 26;12(4):861-5. doi: 10.1097/00001756-200103260-00047.
Although residual vision in patients with cortical blindness is common, its brain mechanisms are poorly known. To study these mechanisms we measured neuromagnetic responses to visual stimuli in a patient with right posterior cerebral lesion and left visual field hemianopia. His vision had partially recovered with intensive training before our measurements. Compared with the processing in the healthy side, early occipital responses were attenuated for both passive viewing of checkerboard reversal patterns and a letter identification task. In both conditions there were prominent longer-latency responses at the right superior temporal cortex. We suggest that the activation in the superior temporal cortex can partially compensate for the failure to produce synchronized population responses at the early stages of visual cortical processing.
虽然皮质盲患者存在残余视力很常见，但其脑机制却鲜为人知。为研究这些机制，我们测量了一名右侧大脑后叶病变及左侧视野偏盲患者对视觉刺激的神经磁反应。在我们进行测量之前，他的视力通过强化训练已部分恢复。与健康侧的处理过程相比，无论是对棋盘格翻转模式的被动观察还是字母识别任务，早期枕叶反应均减弱。在这两种情况下，右侧颞上皮质均出现了显著的潜伏期更长的反应。我们认为，颞上皮质的激活可部分弥补视觉皮质处理早期未能产生同步群体反应的缺陷。
