Wellcome Laboratory of Neurobiology, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
Wellcome Laboratory of Neurobiology, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
Neuroimage. 2016 Jul 1;134:532-539. doi: 10.1016/j.neuroimage.2016.03.078. Epub 2016 Apr 13.
Visual evoked potentials have been traditionally triggered with flash or reversing checkerboard stimuli and recorded with electroencephalographic techniques, largely but not exclusively in clinical or clinically related settings. They have been crucial in determining the healthy functioning or otherwise of the visual pathways up to and including the cerebral cortex. They have typically given early response latencies of 100ms, the source of which has been attributed to V1, with the prestriate cortex being secondarily activated somewhat later. On the other hand, magnetoencephalographic studies using stimuli better tailored to the physiology of individual, specialized, visual areas have given early latencies of <50ms with the sources localized in both striate (V1) and prestriate cortex. In this study, we used the reversing checkerboard pattern as a stimulus and recorded cortical visual evoked magnetic fields with magnetoencephalography, to establish whether very early responses can be traced to (estimated) in both striate and prestriate cortex, since such a demonstration would enhance considerably the power of this classical approach in clinical investigations. Our results show that cortical responses evoked by checkerboard patterns can be detected before 50ms post-stimulus onset and that their sources can be estimated in both striate and prestriate cortex, suggesting a strong parallel input from the sub-cortex to both striate and prestriate divisions of the visual cortex.
视觉诱发电位传统上采用闪光或反转棋盘刺激来触发，并用电生理学技术进行记录，主要但不仅限于临床或临床相关环境中。它们在确定视觉通路的健康功能或其他方面至关重要，包括大脑皮层。它们通常具有 100ms 的早期反应潜伏期，其来源归因于 V1，而纹状皮层稍后会被二级激活。另一方面，使用更适合个体、专门的视觉区域生理学的刺激进行的脑磁图研究给出了 <50ms 的早期潜伏期，其源位于纹状皮层（V1）和纹状前皮层。在这项研究中，我们使用反转棋盘模式作为刺激，并使用脑磁图记录皮质视觉诱发电磁场，以确定非常早期的反应是否可以追溯到（估计）纹状和纹状前皮层，因为这样的证明将极大地增强这种经典方法在临床研究中的效力。我们的结果表明，棋盘模式引起的皮质反应可以在刺激后 50ms 之前检测到，并且它们的源可以在纹状和纹状前皮层中进行估计，这表明来自皮质下的强平行输入到视觉皮质的纹状和纹状前部分。
