Intermodulation components of the visual evoked potential: Responses to lateral and superimposed stimuli
Intermodulation components of the visual evoked potential: Responses to lateral and superimposed stimuli
复制标题
DOI：
10.1007/bf00335197
复制
发表时间：
2004
影响因子：
1.9
通讯作者：
V. Zemon;F. Ratliff
中科院分区：
文献类型：
--
作者：
V. Zemon;F. Ratliff
利用视觉诱发电位（VEP）研究了人类视觉系统中的非线性相互作用。在一个实验（叠加条件）中，飞镖靶图案的所有片段都通过两个正弦信号的总和在时间上进行对比度反转。在第二个实验（lateralcondition）中，在飞镖靶图案的某些区域中的片段通过一个频率的单个正弦曲线进行对比度反转，而在图案的其他（连续）区域中的片段通过另一个频率的单个正弦曲线进行对比度反转。在每个实验中使用相同的一组十个频率对。选择频率对，使得每对中的频率之间的差为2Hz。振幅和相位的总和和差频分量的VEP（互调项）进行检索傅立叶分析，并作为非线性相互作用的措施。使用具有固定频率间隔的输入对使得能够在第二线性阶段之前估计视觉通路的时间特性。使用叠加和lateralconditions揭示拮抗贡献的VEP，可能反映直接通过兴奋和侧抑制途径，分别。
Nonlinear interactions in the human visual system were studied using visual evoked potentials (VEPs). In one experiment (superimposedcondition), all segments of a dartboard pattern were contrast reversed in time by a sum of two sinusoidal signals. In a second experiment (lateralcondition), segments in some regions of the dartboard pattern were contrast reversed by a single sinusoid of one frequency, while segments in other (contiguous) regions of the pattern were contrast reversed by a single sinusoid of another frequency. An identical set of ten frequency pairs was used in each experiment. The frequency pairs were chosen such that the difference between frequencies in each pair was 2 Hz. Amplitudes and phases of the sum and difference frequency components of the VEP (intermodulation terms) were retrieved by Fourier analysis and served as measures of nonlinear interactions. The use of input pairs with a fixed separation in frequency enabled the estimation of the temporal characteristics of the visual pathways prior to a second linear stage. The use ofsuperimposedandlateralconditions revealed antagonistic contributions to the VEP, possibly reflecting direct-through excitatory and lateral inhibitory pathways, respectively.