Neuronal activity and attention in the primary visual cortex

为了研究在视野中广泛分布的刺激信息整合的机制，我们在麻醉猫的初级视皮层中观察了栅格刺激对初级视觉皮层神经元视觉反应的调制效应。在感受野中，对最佳定向的光栅贴片的反应受到周围刺激的抑制，特别是在表层的复杂细胞中。周围刺激的有效性取决于细胞的首选空间频率(SF)和周围栅格的SF之间的关系。在有周围刺激存在的21个细胞中，周围刺激对抑制调制的最有效SF与感受野刺激的最佳SF相同的有12个，不同的有6个。在其余3个细胞中，未观察到SF对SF反应调制的依赖性。我们的结果表明，具有相似SF偏好的SF域之间的神经联系是视皮层反应的语境调制的基础之一。

To study mechanisms for an integration of stimulus information distributing wide area in the visual field, we examined modulatory effects of visual responses of neurons by grating stimuli presented outside of receptive field in the primary visual cortex of anesthetized cats. Responses to the optimally oriented grating patch in the receptive field were suppressed by surrounding stimulus particularly in complex cells of the superficial layer. Effectiveness of surrounding stimulus was dependent on relationship between the cell's preferred spatial frequency (SF) and the SF of surrounding grating. Among the 21 cells which exhibited significant suppression with a presence of surrounding stimulus, the most effective SF of surrounding stimulus for the suppressive modulation was same as that of the optimal SF for the receptive field stimulus in 12 cells and different in 6 cells. In remaining 3 cells, SF dependency of the response modulation by SF was not observed. Our results suggest that neural connection among SF domains sharing similar SF preference is one of the basis of the contextual modulation of responses in the visual cortex.