Ribot Jérôme, Tanaka Shigeru, O'Hashi Kazunori, Ajima Ayako
Laboratory for Visual Neurocomputing, RIKEN Brain Science Institute, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan.
Eur J Neurosci. 2008 May;27(10):2773-80. doi: 10.1111/j.1460-9568.2008.06219.x. Epub 2008 May 16.
Higher visual cortical areas are involved in the perception of complex stimuli, such as the optic flow created by self-motion. On the other hand, area 18 is thought to extract primitive visual features, feeding higher cortical areas for further processing. In this study, we applied optical imaging of intrinsic signals in the central, lower visual field of cat area 18, and reconstructed direction preference and direction selectivity maps in each hemisphere. We observed a significant overrepresentation of downward and temporal directions, in accordance with previous electrophysiological results. Cardinal orientations were not overrepresented, however. Downward directions were overrepresented at the highest direction selectivity domains. Temporal direction representation, on the other hand, decreased with direction selectivity. Our findings therefore suggest the existence of a neural substrate for the processing of optic flow in cat area 18.
更高层次的视觉皮层区域参与复杂刺激的感知,比如自我运动产生的视觉流。另一方面,18区被认为可提取原始视觉特征,为更高层次的皮层区域提供信息以进行进一步处理。在本研究中,我们对猫18区中央下部视野进行了内在信号的光学成像,并重建了每个半球的方向偏好和方向选择性图谱。与之前的电生理结果一致,我们观察到向下和颞侧方向存在显著的过度表征。然而,主要方向并未过度表征。向下方向在最高方向选择性区域过度表征。另一方面,颞侧方向表征随方向选择性降低。因此,我们的研究结果表明猫18区存在处理视觉流的神经基质。