Welchman Andrew E, Lam Judith M, Bülthoff Heinrich H
School of Psychology, University of Birmingham, Edgbaston B15 2TT, United Kingdom.
Proc Natl Acad Sci U S A. 2008 Aug 19;105(33):12087-92. doi: 10.1073/pnas.0804378105. Epub 2008 Aug 12.
Determining the approach of a moving object is a vital survival skill that depends on the brain combining information about lateral translation and motion-in-depth. Given the importance of sensing motion for obstacle avoidance, it is surprising that humans make errors, reporting an object will miss them when it is on a collision course with their head. Here we provide evidence that biases observed when participants estimate movement in depth result from the brain's use of a "prior" favoring slow velocity. We formulate a Bayesian model for computing 3D motion using independently estimated parameters for the shape of the visual system's slow velocity prior. We demonstrate the success of this model in accounting for human behavior in separate experiments that assess both sensitivity and bias in 3D motion estimation. Our results show that a surprising perceptual error in 3D motion perception reflects the importance of prior probabilities when estimating environmental properties.
确定移动物体的行进方向是一项至关重要的生存技能，这依赖于大脑整合有关横向平移和深度运动的信息。鉴于感知运动对避障的重要性，令人惊讶的是，人类会出现错误，当物体正朝着他们头部的碰撞路线移动时，却报告该物体会错过他们。在这里，我们提供证据表明，当参与者估计深度运动时观察到的偏差源于大脑对有利于慢速度的“先验”的运用。我们构建了一个贝叶斯模型，用于使用视觉系统慢速度先验形状的独立估计参数来计算三维运动。我们在单独的实验中证明了该模型在解释三维运动估计中的敏感性和偏差方面人类行为的成功。我们的结果表明，三维运动感知中一个惊人的感知错误反映了估计环境属性时先验概率的重要性。
