Harding G F, Armstrong R A, Janday B
Department of Vision Sciences, Aston University, Birmingham, UK.
Ophthalmic Physiol Opt. 1992 Apr;12(2):171-4. doi: 10.1111/j.1475-1313.1992.tb00284.x.
The visual evoked magnetic response to half-field stimulation using pattern reversal was studied using a d.c. SQUID coupled to a second order gradiometer. The main component of the magnetic response consisted of a positive wave at around 100 ms (P100M). At the time this component was present the response to half-field stimulation consisted of an outgoing magnetic field contralateral and extending to the midline. When the left half field was stimulated the outgoing field was over the posterior right visual cortex and when the right half field was stimulated it was over the left anterior visual cortex. These findings would correctly identify a source located in the contralateral visual cortex. The orientation of the dipoles was not that previously assumed to explain the paradoxical lateralization of the visual evoked potential. The results are discussed in terms of both electrical and magnetic models of the calcarine fissure.
使用与二阶梯度计耦合的直流超导量子干涉装置（d.c. SQUID），研究了模式反转对半视野刺激的视觉诱发磁反应。磁反应的主要成分是在大约100毫秒时出现的一个正波（P100M）。在该成分出现时，对半视野刺激的反应由对侧且延伸至中线的外向磁场组成。当刺激左半视野时，外向磁场位于右后视觉皮层上方；当刺激右半视野时，外向磁场位于左前视觉皮层上方。这些发现能正确识别位于对侧视觉皮层的一个源。偶极子的方向并非先前假定用于解释视觉诱发电位矛盾性偏侧化的方向。根据距状裂的电模型和磁模型对结果进行了讨论。
