NEURONS IN MONKEY PARIETAL AREA LIP ARE TUNED FOR EYE-MOVEMENT PARAMETERS IN 3-DIMENSIONAL SPACE
NEURONS IN MONKEY PARIETAL AREA LIP ARE TUNED FOR EYE-MOVEMENT PARAMETERS IN 3-DIMENSIONAL SPACE
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DOI：
10.1152/jn.1995.73.1.280
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发表时间：
1995-01-01
影响因子：
2.5
通讯作者：
MAYS, LE
中科院分区：
文献类型：
--
作者：
GNADT, JW;MAYS, LE
1.先前已证明（Gnadt和Andersen 1988）顶内沟外侧岸LIP区域中的一类功能神经元与扫视眼球运动的指标相关。本研究我们测试了LIP神经元相对于固定平面的不同深度。61个神经元被鉴定为在扫视眼球运动之前活动增加。在保持目标位置恒定在额平行（扫视）反应场的中心的同时，神经元在眼球运动期间系统地休息到目标位置近端（近端）的固定平面，在固定平面，和远端（远）的固定平面。出于必要，对这些目标的运动需要眼跳和聚散运动的结合。3. 72%的神经元被发现改变其活动作为一个功能的目标深度相对于平面的固定。神经元对深度的调谐曲线很宽。有些细胞喜欢“近”的目标位置，有些喜欢“远”的位置。而其他人在注视的额平行面反应最好.无论目标深度如何，神经元在额肌平面上的反应位置保持不变。然而.当目标位于优选深度时，神经元的反应幅度增加，而当目标位于非优选深度时，神经元的反应幅度减少。这表明神经元总是与相同的额平行坐标相关，但当目标位于其首选深度时反应更强烈。视觉显示装置允许独立呈现两个刺激线索的深度：双眼视差和重复的需求，而其他线索保持不变。对于许多神经元来说，任何一种线索都足以调整深度活动，尽管大多数神经元对两种线索的几何适当组合的反应最好。双眼深度调谐与个体单眼响应的比较表明，深度调谐不是由两个单眼响应场的简单线性组合产生的.我们在一个双重运动任务中测试了一组神经元，该任务将视觉刺激的视网膜坐标与第二运动的眼动坐标分离。这些测试证实了早期的发现，即当眼球运动坐标进入神经元的反应区时，这类功能神经元是活跃的。这是没有必要的视觉刺激落在神经元的反应举行他们变得活跃。8.这项研究和以前的调查表明，这些神经元不是唯一依赖于视网膜上的刺激参数，但更直接的运动空间参数表示当前的眼睛位置和期望的眼睛位置的差异。我们在这里建议，这些神经元表达一个运动前信号，用于指导在三维空间编码的凝视。
1. A functional class of neurons in area LIP on the lateral bank of the intraparietal sulcus were shown previously (Gnadt and Andersen 1988) to be related to the metrics of saccadic eye move ments. In this study. we tested LIP neurons at different depths with respect to the plane of fixation.2. Sixty-one neurons were identified for their increased activity before saccadic eye movements. While holding the location of the target constant at the center of the frontoparallel (saccadic) response field, the neurons were rested systematically during eye movements to target positions proximal (near) to the plane of fixation, at the plane of fixation, and distal (far) to the plane of fixation. By necessity, the movements to these targets required a combination of saccadic and vergence movements.3. Seventy-two percent of the neurons were found to change their activity as a function of target depth relative to the plane of fixation. The neurons had broad tuning curves for depth. Some cells preferred ''near'' target positions, some preferred ''far'' positions. and others responded best in the frontoparallel plane of fixation.4. The location of a neuron's response held in the frontoparellel plane remained constant regardless of target depth. However. the magnitude of the neuron's response increased when the target was positioned at the preferred depth and it decreased for targets positioned at nonpreferred depths. This indicated that the neurons always were related to the same frontoparallel coordinates, but responded more vigorously when the target was positioned at its preferred depth.5. The visual display apparatus allowed independent presentation of two stimulus cues for depth: binocular disparity and accommodative demand whereas other cues were held constant. For many neurons, either cue was sufficient to tune the activity in depth, though most neurons responded best for the geometrically appropriate combination of the two cues.6. Comparison of the binocular tuning for depth with the individual monocular responses showed that the tuning for depth was not produced by simple linear combination of two monocular response fields.7. We tested a subset of the neurons in a double-movement task that dissociated the retinal coordinates of the visual stimuli from the eye-movement coordinates of the second movement. These tests confirmed earlier findings that this functional class of neurons are active when the eye-movement coordinates marched the neurons' response field. It was not necessary For a visual stimulus to fall within the neurons' response held for them to become active.8. This study and previous investigations have shown that these neurons are not uniquely dependent on the stimulus parameters on the retina, but more directly to the motor spatial parameters representing the difference in current eye position and desired eye position. We suggest here that these neurons express a premotor signal for directing gaze that is encoded in three-dimensional space.