Shared computational mechanism for tilt compensation accounts for biased verticality percepts in motion and pattern vision
Shared computational mechanism for tilt compensation accounts for biased verticality percepts in motion and pattern vision
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DOI：
10.1152/jn.00921.2007
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发表时间：
2008-02-01
影响因子：
2.5
通讯作者：
Van Gisbergen, J. A. M.
中科院分区：
文献类型：
--
作者：
De Vrijer, M.;Medendorp, W. P.;Van Gisbergen, J. A. M.
为了确定物体在外部空间中的运动方向，大脑必须将视网膜运动信号和眼睛在空间中的方向信息结合起来。我们评估了这一过程的准确性，在8名横向倾斜的受试者中，他们将随机点模式的运动方向（30%一致性，以6度/秒的速度移动）与他们感知的重力方向（垂直运动）对齐，否则完全黑暗。为了比较，我们还测试了将可调节的视觉线（直径12度）与重力方向（直线垂直）对齐的能力。对于小的头部倾斜（60度）显示了一个大的系统误差模式（通常是30度），这在两个任务中几乎是相同的。回归分析证实，两个任务的平均误差密切相关，斜率接近1.0，相关系数>0.89。控制实验排除了运动设置是基于对单个单点路径的处理。我们得出的结论是，将视网膜上的运动方向和直线方向转换为空间参考框架涉及共享计算策略。两种空间定向模型的模拟表明，系统误差的模式可能是在参考坐标系转换之前处理倾斜信号缺陷的最佳策略的缺点。
To determine the direction of object motion in external space, the brain must combine retinal motion signals and information about the orientation of the eyes in space. We assessed the accuracy of this process in eight laterally tilted subjects who aligned the motion direction of a random-dot pattern (30% coherence, moving at 6 degrees/s) with their perceived direction of gravity (motion vertical) in otherwise complete darkness. For comparison, we also tested the ability to align an adjustable visual line (12 degrees diameter) to the direction of gravity (line vertical). For small head tilts ( 60 degrees revealed a pattern of large systematic errors (often >30 degrees) that was virtually identical in both tasks. Regression analysis confirmed that mean errors in the two tasks were closely related, with slopes close to 1.0 and correlations >0.89. Control experiments ruled out that motion settings were based on processing of individual single-dot paths. We conclude that the conversion of both motion direction and line orientation on the retina into a spatial frame of reference involves a shared computational strategy. Simulations with two spatial-orientation models suggest that the pattern of systematic errors may be the downside of an optimal strategy for dealing with imperfections in the tilt signal that is implemented before the reference-frame transformation.