Patterson Gentile Carlyn, Aguirre Geoffrey Karl
,.
J Vis. 2020 Jul 1;20(7):11. doi: 10.1167/jov.20.7.11.
The theory of "visual stress" holds that visual discomfort results from overactivation of the visual cortex. Despite general acceptance, there is a paucity of empirical data that confirm this relationship, particularly for discomfort from visual flicker. We examined the association between neural response and visual discomfort using flickering light of different temporal frequencies that separately targeted the LMS, L-M, and S postreceptoral channels. Given prior work that has shown larger cortical responses to flickering light in people with migraine, we examined 10 headache-free people and 10 migraineurs with visual aura. The stimulus was a uniform field, 50 degrees in diameter, that modulated with high-contrast flicker between 1.625 and 30 Hz. We asked subjects to rate their visual discomfort while we recorded steady-state visually evoked potentials (ssVEPs) from early visual cortex. The peak temporal sensitivity ssVEP amplitude varied by postreceptoral channel and was consistent with the known properties of these visual channels. There was a direct, linear relationship between the amplitude of neural response to a stimulus and the degree of visual discomfort it evoked. No substantive differences between the migraine and control groups were found. These data link increased visual cortical activation with the experience of visual discomfort.
“视觉应激”理论认为，视觉不适是由视觉皮层过度激活所致。尽管该理论已被广泛接受，但证实这种关系的实证数据却很匮乏，尤其是关于视觉闪烁引起的不适。我们使用不同时间频率的闪烁光分别针对LMS、L-M和S后感受器通道，研究了神经反应与视觉不适之间的关联。鉴于先前的研究表明偏头痛患者对闪烁光的皮层反应更大，我们对10名无头痛者和10名有视觉先兆的偏头痛患者进行了研究。刺激物是一个直径50度的均匀视野，以1.625至30赫兹的高对比度闪烁进行调制。在我们从早期视觉皮层记录稳态视觉诱发电位（ssVEP）时，要求受试者对他们的视觉不适进行评分。峰值时间敏感性ssVEP振幅因后感受器通道而异，并且与这些视觉通道的已知特性一致。对刺激的神经反应幅度与它所引起的视觉不适程度之间存在直接的线性关系。未发现偏头痛组和对照组之间有实质性差异。这些数据将视觉皮层激活增加与视觉不适体验联系了起来。
