The mechanisms underlying cortical motion selectivity

描述（由申请人提供）：大脑用来快速处理信息的一种策略是使用多条平行路径同时分析世界的不同方面。视觉场景的分析被认为分为三个平行的路径，分别用于处理颜色、形状和运动。在这项研究中，我们将研究视觉皮层中第三条通路——运动选择性的神经元机制。V1的运动处理需要皮质神经元选择性地对世界上移动物体的方向和速度做出反应。方向选择性是一种在V1神经元中重新产生的神经元反应特性：它不存在于向皮层提供视觉输入的外侧膝状核（LGN）的神经元中。与其他纯粹的空间反应特性（如方向选择性）不同，方向选择性需要在时间域和空间域进行处理：方向选择性神经元不仅必须识别物体的位置，而且必须识别它在前一刻的位置。因此，方向选择性被认为是通过结合来自不同感受野位置和不同时间延迟的LGN神经元的输入而产生的。

DESCRIPTION (provided by applicant): One strategy the brain uses to process information rapidly is the use of multiple parallel pathways to analyze different aspects of the world simultaneously. The analysis of a visual scene is thought to be segregated into three parallel pathways dedicated to the processing of color, shape, and motion. During this fellowship we will study the neuronal mechanisms that underlie the third pathway, motion selectivity, in visual cortex. Motion processing in V1 requires cortical neurons that respond selectively to the direction and speed of moving objects in the world. Direction selectivity is a neuronal response property that is created de novo in V1 neurons: it is not present in the neurons of the lateral geniculate nucleus (LGN) that provide visual input to the cortex. Unlike other purely spatial response properties such as orientation selectivity, direction selectivity requires processing in the time domain as well as the space domain: direction selective neurons must discern not only where an object is, but where it was in the previous moment. Direction selectivity is therefore thought to be created by combining inputs from LGN neurons with different receptive field positions and different temporal delays. We will investigate how the signals from the LGN are transformed and combined to give neurons in V1 their directionally selective responses. By studying and understanding direction selectivity, we will learn the rules of information processing that may apply generally to cortical processing of temporal information.