Handa Takashi, Unno Shumpei, Mikami Akichika
aDepartment of Behavioral and Brain Sciences, Primate Research Institute, Kyoto University, Inuyama bDepartment of Oral Physiology, School of Dentistry, Matsumoto Dental University, Shiojiri cFaculty of Nursing and Rehabilitation, Chubu Gakuin University, Seki, Japan dDepartment of Behavior and Brain Organization, Center of Advanced European Studies and Research (caesar), Bonn, Germany.
Neuroreport. 2017 Sep 6;28(13):793-799. doi: 10.1097/WNR.0000000000000826.
In the primate brain, shape and motion are considered to be separately processed in the ventral and dorsal visual cortical areas, respectively. However, to achieve shape perception with a motion cue, shape and motion cannot be processed exclusively in separate cortical areas. Interactions between ventral and dorsal cortical areas are required, and yet, the neural mechanisms underlying motion-defined shape perception remain unclear. Here, we assessed the temporal properties of single-unit activity recorded from V4, the middle temporal area, and the anterior superior temporal sulcus while monkeys discriminated shapes defined by motion and luminance cues. Visual response latencies of V4 neurons were shorter in the luminance-cue condition than in the motion-cue condition. Meanwhile, the timings of initiation of shape selectivity were not different between cue conditions, indicating a difference in processing time. Middle temporal neurons were less shape modulated in the luminance-cue condition than in the motion-cue condition. Temporal properties of neural activities in the lower bank of anterior superior temporal sulcus were similar between cue conditions. These results suggest that an interaction of the ventral cortex with the dorsal cortex is required for shape discrimination with different visual cues.
在灵长类动物大脑中，形状和运动分别被认为是在腹侧和背侧视觉皮层区域进行处理的。然而，为了通过运动线索实现形状感知，形状和运动不能仅在单独的皮层区域进行处理。腹侧和背侧皮层区域之间需要相互作用，然而，基于运动定义的形状感知的神经机制仍不清楚。在这里，当猴子区分由运动和亮度线索定义的形状时，我们评估了从V4区、颞中区和颞上沟前部记录的单个神经元活动的时间特性。在亮度线索条件下，V4神经元的视觉反应潜伏期比在运动线索条件下短。同时，在不同线索条件下，形状选择性开始的时间没有差异，这表明处理时间存在差异。在亮度线索条件下，颞中神经元的形状调制比在运动线索条件下少。颞上沟前部下缘神经活动的时间特性在不同线索条件下相似。这些结果表明，腹侧皮层与背侧皮层的相互作用是利用不同视觉线索进行形状辨别的必要条件。
