Anisotropy in spatial summation properties of human Ocular-Following Response (OFR).
Anisotropy in spatial summation properties of human Ocular-Following Response (OFR).
复制标题
人类眼球跟随响应 (OFR) 空间总和特性的各向异性。
DOI：
10.1016/j.visres.2015.02.015
复制
发表时间：
2015
期刊：
影响因子：
1.8
通讯作者：
Cumming,BG
中科院分区：
文献类型：
--
作者：
Sheliga,BM;Quaia,C;FitzGibbon,EJ;Cumming,BG
利用正弦光栅，我们发现，在与运动轴垂直的尺寸范围内，刺激大小的增加会导致更强的眼球跟随反应(OFR)，直到某个最佳大小。超过这一最佳值的增加会产生较小的反应，表明相互作用受到抑制。与之形成鲜明对比的是，当刺激增长平行于运动轴时，OFR的幅度在水平和垂直运动方向上都是单调增加的。对于一维白噪声模式，也得到了类似的结果。然而，在二维白噪声模式下，OFR的空间各向异性是最小的，这揭示了定向选择(即，皮质)机制在调节这一现象中的关键作用。2D图案的各向异性的缺乏表明方向信号本身不足以引起这种抑制。如果静止的光栅在运动开始前呈现600-1000毫秒，则OFR的空间各向异性被增强，从而进一步强调了静态取向信号的重要性。这些结果表明，大脑皮质空间相互作用的强度是不对称的--即，在末端的方向上大于定向选择性感受野的侧翼--这证实了现有的神经生理学证据。
Using sinusoidal gratings we show that an increase in stimulus size confined to the dimension orthogonal to the axis of motion leads to stronger Ocular Following Responses (OFRs) up to a certain optimal size. An increase beyond this optimum produces smaller responses, indicating suppressive interactions. In sharp contrast, when the stimulus growth occurs parallel to the axis of motion OFR magnitudes increase monotonically both for horizontal and vertical directions of motion. Similar results are obtained with 1D white noise patterns. However, the OFR spatial anisotropy is minimal with 2D white noise patterns, revealing a pivotal role of orientation-selective (i.e., cortical) mechanisms in mediating this phenomenon. The lack of anisotropy for 2D patterns suggests that directional signals alone are not sufficient to elicit this suppression. The OFR spatial anisotropy is potentiated if a stationary grating is presented for 600–1000 ms before its motion commences, further emphasizing the importance of static orientation signals. These results suggest that the strength of cortical spatial interactions is asymmetric—i.e., larger in the direction of the ends than the flanks of an orientation-selective receptive field—which corroborates the existing neurophysiological evidence.