Heggelund P, Moors J
Exp Brain Res. 1983;52(2):235-47. doi: 10.1007/BF00236632.
The relationship between orientation selectivity and spatial receptive field organization was analyzed. Receptive field maps were made with a dual stimulus technique where an optimally oriented activation slit was presented in the most responsive region to produce activity against which the effect of a test spot in various positions was determined. Both simple and complex cells had receptive fields which were subdivided into adjacent elongated and antagonistic subregions. When the two stimuli were presented in phase (both ON or OFF simultaneously) the fields had a central enhancement region with a strong suppression flank on one or both sides. Optimal slit orientation was related to the location of the suppression flank relative to the location of the central enhancement region, and the degree of orientation selectivity to the shape of the subregions and the distance between them. Estimated orientation tuning curves calculated from the receptive field maps gave satisfactory first approximations to experimental curves. The relative contribution of enhancement and suppression to orientation selectivity was studied by presenting a test slit in different orientations in phase with an optimally oriented activation slit. The orientation selectivity was produced almost exclusively by the flank suppression indicating that orientation selectivity is produced by inhibitory input. The flank suppression lacked any specific orientation selectivity, and it occurred only when both the central region and the flanks were activated in phase. Orientation selectivity in both simple and complex cells is explained by a receptive field organization where the cells have input from partially overlapping excitatory and inhibitory fields which have their centers slightly displaced from each other.
分析了方向选择性与空间感受野组织之间的关系。使用双刺激技术绘制感受野图，即在最敏感区域呈现一个最佳方向的激活狭缝以产生活动，据此确定测试点在不同位置时的影响。简单细胞和复杂细胞的感受野都被细分为相邻的细长且相互拮抗的子区域。当两个刺激同相呈现（同时开启或关闭）时，感受野有一个中央增强区域，其一侧或两侧有强烈的抑制侧翼。最佳狭缝方向与抑制侧翼相对于中央增强区域位置有关，方向选择性程度与子区域形状及其之间的距离有关。根据感受野图计算出的估计方向调谐曲线与实验曲线给出了令人满意的初步近似。通过在与最佳方向的激活狭缝同相的不同方向上呈现测试狭缝，研究了增强和抑制对方向选择性的相对贡献。方向选择性几乎完全由侧翼抑制产生，这表明方向选择性是由抑制性输入产生的。侧翼抑制缺乏任何特定的方向选择性，并且仅在中央区域和侧翼都同相激活时才会发生。简单细胞和复杂细胞中的方向选择性都可以通过一种感受野组织来解释，即细胞从部分重叠的兴奋性和抑制性场接收输入，这些场的中心彼此稍有偏移。
