Mohr Kieran S, Geuzebroek Anna C, Kelly Simon P
School of Electrical and Electronic Engineering and UCD Centre for Biomedical Engineering, UCD Engineering and Materials Science Centre, University College Dublin, Belfield, Ireland.
https://orcid.org/0000-0002-6165-7810.
J Vis. 2025 Jun 2;25(7):1. doi: 10.1167/jov.25.7.1.
The multifocal visual evoked potential (mVEP), elicited by either pattern-pulses or pattern-reversals, provides an effective means to study visual processing and to identify retinal damage and visual field defects. It is often assumed that the first components of these VEPs, the C1 and N75, respectively, are generated in V1, based on source modeling and their polarity reversal between upper- and lower-field stimulus presentations. However, limitations in the spatial resolution of source modeling and the non-uniqueness of the polarity reversal heuristic leave this assumed V1 source uncertain. We recently demonstrated the utility of a novel method to resolve visual sources by correlating retinotopically varying VEP topographies with predictions from the Benson-2014 retinotopy atlas. Here, we apply this method to study the sources of both the pulse and reversal mVEP, presented at the same stimulus event rates of between 3-8 Hz per location (approximately 35 Hz overall event rate). This analysis suggested that although V1 dominated the generation of the pulse mVEP throughout its time course, the initial component of the reversal mVEP was instead dominated by extrastriate areas, with V1 dominance emerging later from approximately 110 ms onwards. Although the initial component of the reversal mVEP did exhibit the classic sign of a V1 source-polarity reversal across the horizontal meridian-this basic feature is also produced by extrastriate areas such as V2 and V3, and the strong lateralization of topographies near the vertical meridian predicted by a V1 source was not observed. These results suggest that the pulse and reversal mVEP evoke different cascades of generative visual areas when evoked at the event rate tested here.
由模式脉冲或模式反转诱发的多焦点视觉诱发电位（mVEP），为研究视觉处理以及识别视网膜损伤和视野缺损提供了一种有效的手段。基于源模型以及它们在上下视野刺激呈现之间的极性反转，人们通常认为这些VEP的最初成分，即分别为C1和N75，是在V1区产生的。然而，源模型的空间分辨率存在局限性，且极性反转启发法具有非唯一性，这使得这种假定的V1源并不确定。我们最近证明了一种新方法的实用性，该方法通过将视网膜拓扑变化的VEP地形图与Benson - 2014视网膜拓扑图谱的预测结果进行关联来解析视觉源。在此，我们应用这种方法来研究脉冲和反转mVEP的源，它们在每个位置以3 - 8Hz的相同刺激事件率呈现（总体事件率约为35Hz）。该分析表明，尽管在整个时间进程中V1主导了脉冲mVEP的产生，但反转mVEP的初始成分却由纹外区域主导，V1的主导作用从大约110毫秒起才开始显现。尽管反转mVEP的初始成分确实在水平子午线上表现出V1源极性反转的经典特征——但这种基本特征也由V2和V3等纹外区域产生，并且未观察到V1源预测的垂直子午线附近地形图的强烈侧向化。这些结果表明，在此处测试的事件率下诱发时，脉冲和反转mVEP会引发不同的视觉生成区域级联反应。
