Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA, USA.
J Vis. 2022 Nov 1;22(12):12. doi: 10.1167/jov.22.12.12.
Temporal differences in visual information processing between the eyes can cause dramatic misperceptions of motion and depth. Processing delays between the eyes cause the Pulfrich effect: oscillating targets in the frontal plane are misperceived as moving along near-elliptical motion trajectories in depth (Pulfrich, 1922). Here, we explain a previously reported but poorly understood variant: the anomalous Pulfrich effect. When this variant is perceived, the illusory motion trajectory appears oriented left- or right-side back in depth, rather than aligned with the true direction of motion. Our data indicate that this perceived misalignment is due to interocular differences in neural temporal integration periods, as opposed to interocular differences in delay. For oscillating motion, differences in the duration of temporal integration dampen the effective motion amplitude in one eye relative to the other. In a dynamic analog of the Geometric effect in stereo-surface-orientation perception (Ogle, 1950), the different motion amplitudes cause the perceived misorientation of the motion trajectories. Forced-choice psychophysical experiments, conducted with both different spatial frequencies and different onscreen motion damping in the two eyes show that the perceived misorientation in depth is associated with the eye having greater motion damping. A target-tracking experiment provided more direct evidence that the anomalous Pulfrich effect is caused by interocular differences in temporal integration and delay. These findings highlight the computational hurdles posed to the visual system by temporal differences in sensory processing. Future work will explore how the visual system overcomes these challenges to achieve accurate perception.
眼睛之间的视觉信息处理的时间差异会导致运动和深度的明显错觉。眼睛之间的处理延迟会导致普夫吕克效应：在额状面上的振荡目标被误认为是在深度上沿着近椭圆形的运动轨迹移动（普夫吕克，1922 年）。在这里，我们解释了一个先前报道但理解不佳的变体：异常普夫吕克效应。当感知到这种变体时，虚幻的运动轨迹似乎在深度上向左侧或右侧向后定向，而不是与真实的运动方向对齐。我们的数据表明，这种感知到的错位是由于眼睛之间的神经时间整合周期的差异，而不是眼睛之间的延迟差异。对于振荡运动，时间整合持续时间的差异会使一只眼睛的有效运动幅度相对于另一只眼睛减弱。在立体表面方向感知中的几何效应的动态模拟中（奥格尔，1950 年），不同的运动幅度会导致运动轨迹的感知错位。使用不同的空间频率和两只眼睛中不同的屏幕运动阻尼进行的强制选择心理物理实验表明，深度上的感知错位与具有更大运动阻尼的眼睛有关。一个目标跟踪实验提供了更直接的证据，表明异常普夫吕克效应是由眼睛之间的时间整合和延迟差异引起的。这些发现突出了感觉处理中的时间差异对视觉系统带来的计算障碍。未来的工作将探索视觉系统如何克服这些挑战以实现准确的感知。
