Read Jenny C A, Cumming Bruce G
Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
J Vis. 2005 Dec 19;5(11):901-27. doi: 10.1167/5.11.1.
In the Pulfrich effect, an interocular time delay results in the perception of depth. Two modified versions, the stroboscopic Pulfrich effect and dynamic visual noise with a delay, are generally explained by postulating an early stage of space/time-inseparable filtering, encoding motion and disparity jointly. However, most disparity sensors in monkey V1 do not show joint motion/disparity encoding, and we recently showed that depth perception in the stroboscopic Pulfrich effect is equally compatible with space/time-separable filtering. Here, we demonstrate that this filtering can be implemented with a population of physiologically plausible energy model units. Similar results are obtained whether the neurons are pure disparity sensors (like most V1 neurons) or joint motion/disparity sensors (like MT). We also demonstrate that the dynamic noise stimulus produces correlations between the activity in pure disparity sensors, and in a separate population of pure motion sensors. These correlations are sufficient to explain the percept. Thus, joint encoding of motion and disparity is not required to explain depth perception in Pulfrich-like stimuli: a brain which encoded motion and disparity in entirely separate neuronal pathways could still experience all of these illusions.
在普尔弗里希效应中，两眼间的时间延迟会导致深度感知。两种改进版本，即频闪普尔弗里希效应和带延迟的动态视觉噪声，通常通过假定一个时空不可分离的早期滤波阶段来解释，该阶段联合编码运动和视差。然而，猴子V1区的大多数视差传感器并未表现出联合运动/视差编码，并且我们最近表明频闪普尔弗里希效应中的深度感知同样与时空可分离滤波兼容。在此，我们证明这种滤波可以由一群生理上合理的能量模型单元来实现。无论神经元是纯视差传感器（如大多数V1神经元）还是联合运动/视差传感器（如MT区神经元），都会得到类似的结果。我们还证明动态噪声刺激会在纯视差传感器以及单独的纯运动传感器群体的活动之间产生相关性。这些相关性足以解释这种感知。因此，解释类似普尔弗里希刺激中的深度感知并不需要运动和视差的联合编码：一个在完全分离的神经元通路中编码运动和视差的大脑仍然可能体验到所有这些错觉。
