Hogervorst M A, Eagle R A
Department of Experimental Psychology, University of Oxford, UK.
Proc Biol Sci. 1998 Sep 7;265(1406):1587-93. doi: 10.1098/rspb.1998.0476.
The projected pattern of retinal-image motion supplies the human visual system with valuable information about properties of the three-dimensional environment. How well three-dimensional properties can be recovered depends both on the accuracy with which the early motion system estimates retinal motion, and on the way later processes interpret this retinal motion. Here we combine both early and late stages of the computational process to account for the hitherto puzzling phenomenon of systematic biases in three-dimensional shape perception. We present data showing how the perceived depth of a hinged plane ('an open book') can be systematically biased by the extent over which it rotates. We then present a Bayesian model that combines early measurement noise with geometric reconstruction of the three-dimensional scene. Although this model has no in-built bias towards particular three-dimensional shapes, it accounts for the data well. Our analysis suggests that the biases stem largely from the geometric constraints imposed on what three-dimensional scenes are compatible with the (noisy) early motion measurements. Given these findings, we suggest that the visual system may act as an optimal estimator of three-dimensional structure-from-motion.
视网膜图像运动的预测模式为人类视觉系统提供了有关三维环境属性的宝贵信息。三维属性的恢复程度既取决于早期运动系统估计视网膜运动的准确性，也取决于后期处理解释这种视网膜运动的方式。在这里，我们结合计算过程的早期和后期阶段，以解释迄今为止在三维形状感知中令人困惑的系统偏差现象。我们展示的数据表明，铰接平面（“一本打开的书”）的感知深度如何会因其旋转程度而产生系统性偏差。然后，我们提出了一个贝叶斯模型，该模型将早期测量噪声与三维场景的几何重建相结合。尽管这个模型对特定的三维形状没有内在偏差，但它能很好地解释这些数据。我们的分析表明，这些偏差主要源于对与（有噪声的）早期运动测量兼容的三维场景所施加的几何约束。基于这些发现，我们认为视觉系统可能充当了从运动中获取三维结构的最优估计器。
