Department of Biomedical Engineering, City College of New York, New York, NY 10031, USA.
Neuroimage. 2013 Nov 15;82:154-9. doi: 10.1016/j.neuroimage.2013.05.112. Epub 2013 Jun 2.
Here we summarize the points raised in our dialog with Ales and colleagues on the cortical generators of the early visual evoked potential (VEP), and offer observations on the results of additional simulations that were run in response to our original comment. For small stimuli placed at locations in the upper and lower visual field for which the human VEP has been well characterized, simulated scalp projections of each of the visual areas V1, V2 and V3 invert in polarity. However, the empirically measured, earliest VEP component, "C1," matches the simulated V1 generators in terms of polarity and topography, but not the simulated V2 and V3 generators. We thus conclude that, 1) consistent with the title of Ales et al. (2010a), polarity inversion on its own is not a sufficient criterion for inferring neuroelectric sources in primary visual cortex; but 2) inconsistent with additional claims made in Ales et al. (2010a), the simulated topographies provide additional evidence for - not against - the tenet that the C1 component is generated in V1.
在这里，我们总结了我们与 Ales 及其同事就早期视觉诱发电位 (VEP) 的皮质发生器进行对话中提出的观点，并对根据我们的原始评论进行的额外模拟的结果进行了观察。对于在人类 VEP 特征良好的上、下视野位置处的小刺激，每个视觉区域 V1、V2 和 V3 的模拟头皮投影都会反转极性。然而，从经验上测量的最早的 VEP 成分“C1”在极性和地形上与模拟的 V1 发生器匹配，但与模拟的 V2 和 V3 发生器不匹配。因此，我们得出以下结论：1）与 Ales 等人的标题一致（2010a），极性反转本身并不是推断初级视觉皮层神经电源的充分标准；但 2）与 Ales 等人的其他主张不一致（2010a），模拟地形为这一观点提供了额外的证据，即 C1 成分是在 V1 中产生的，而不是相反。
