Lovasik J V, Ahmedbhai N
Am J Optom Physiol Opt. 1985 May;62(5):334-43. doi: 10.1097/00006324-198505000-00006.
Evoked cortical potentials produced by flash pattern stimulation contain contrast- and luminance-dependent components. In order to elicit contrast-specific responses, reversing checkerboards used to elicit steady-state visually evoked responses (VER's) are designed to have luminance changes in adjacent checks that are equal and opposite so that the net change in the overall checkerboard luminance is zero. Data are presented which demonstrate that commercially available, electronically generated reversing checkerboards on television monitors may contain luminance artifacts sufficiently large to elicit flicker VER's closely resembling genuine contrast VER's. These hidden luminance contaminants may result in erroneous conclusions when assessing visual mechanisms or function.
闪光模式刺激产生的诱发皮层电位包含对比度和亮度依赖性成分。为了引发对比度特异性反应，用于引发稳态视觉诱发电位（VER）的反转棋盘格被设计成相邻方格中的亮度变化相等且相反，以使整个棋盘格亮度的净变化为零。所呈现的数据表明，电视监视器上市售的电子生成反转棋盘格可能包含足够大的亮度伪影，足以引发与真正的对比度VER非常相似的闪烁VER。在评估视觉机制或功能时，这些隐藏的亮度污染物可能导致错误的结论。
