Viviani P, Aymoz C
Department of Psychobiology, Faculty of Psychology and Educational Science, University of Geneva, 40 Bd du Pont d'Arve, 1205 Geneva CH, Switzerland.
Vision Res. 2001 Oct;41(22):2909-18. doi: 10.1016/s0042-6989(01)00160-2.
Behavioural, neuro-anatomical and clinical evidence suggests that different aspects of the visual scene are processed separately, but the extent to which the processing is carried out along segregated and independent parallel pathways is still debated. Moreover, it is also unclear whether these aspects are processed at the same rate, and their neural correlates reach consciousness at the same time. An experiment investigated this issue in the case of three attributes of 2D displays: colour, form, and movement. There were three conditions, one for each possible pairing of these attributes. Stimuli were combinations of two values for each attribute (red/green, circle/square, fixed/moving). In each condition the stimuli changed twice in close temporal succession, each attribute switching asynchronously between the two possible values. The observer's task was to report which change had occurred first. Response probabilities were computed for 13 values of the asynchrony, and transformed into estimates of perception time with the help of a psychophysical model. The results showed that colour and form are processed almost simultaneously. By contrast, movement perception is delayed by about 50 ms. The implications of these findings vis à vis the so-called perceptual binding problem are discussed.
行为学、神经解剖学和临床证据表明，视觉场景的不同方面是分开处理的，但这种处理在多大程度上沿着分离且独立的平行通路进行仍存在争议。此外，这些方面是否以相同的速度进行处理，以及它们的神经关联是否同时进入意识也尚不清楚。一项实验针对二维显示器的三个属性（颜色、形状和运动）研究了这个问题。有三种条件，每种条件对应这些属性的一种可能配对。刺激是每个属性的两个值的组合（红/绿、圆/方、静止/运动）。在每种条件下，刺激在紧密的时间序列中变化两次，每个属性在两个可能的值之间异步切换。观察者的任务是报告哪个变化先发生。计算了13个异步值的反应概率，并借助心理物理学模型将其转换为感知时间的估计值。结果表明，颜色和形状几乎是同时处理的。相比之下，运动感知延迟约50毫秒。讨论了这些发现对于所谓的感知绑定问题的意义。
