The emergence of visual objects in space-time
The emergence of visual objects in space-time
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DOI：
10.1073/pnas.97.14.8186
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发表时间：
2000-07-05
影响因子：
11.1
通讯作者：
Kubovy, M
中科院分区：
文献类型：
--
作者：
Gepshtein, S;Kubovy, M
人们很自然地会认为，在感知动态场景时，视觉会拍摄一系列快照。当快照不同时，运动感知就会产生。快照这一比喻引出了两个问题：（i）视觉系统如何将每个快照中的元素组合在一起形成物体？这是空间分组问题。（ii）当快照不同时，视觉系统如何知道一个快照中的哪个元素与下一个快照中的哪个元素相对应？这是时间分组问题。快照比喻是该领域占主导地位的模型——序列模型的一种夸张表述，根据该模型，空间分组和时间分组是相互独立的。我们在此提出的模型是一个交互模型，根据该模型，这两种分组机制是不可分离的。目前，支持交互模型的实验尚无定论，因为它们使用的刺激过于特殊。为了克服这一弱点，我们创造了一种新型的刺激——时空点阵，它使我们能够独立地操控空间分组和时间分组的强度。对于这些刺激，序列模型有一个基本假设：如果刺激的空间配置保持不变，那么对空间分组的感知就不会受到对刺激时间配置的操控的影响。我们的数据与这一假设不一致。
It is natural to think that in perceiving dynamic scenes, vision takes a series of snapshots. Motion perception can ensue when the snapshots are different. The snapshot metaphor suggests two questions: (i) How does the visual system put together elements within each snapshot to form objects? This is the spatial grouping problem. (ii) When the snapshots are different, how does the visual system know which element in one snapshot corresponds to which element in the next? This is the temporal grouping problem. The snapshot metaphor is a caricature of the dominant model in the field-the sequential model-according to which spatial and temporal grouping are independent. The model we propose here is an interactive model, according to which the two grouping mechanisms are not separable. Currently, the experiments that support the interactive model are not conclusive because they use stimuli that are excessively specialized. To overcome this weakness, we created a new type of stimulus-spatiotemporal dot lattices-which allow us to independently manipulate the strength of spatial and temporal groupings. For these stimuli, sequential models make one fundamental assumption: if the spatial configuration of the stimulus remains constant, the perception of spatial grouping cannot be affected by manipulations of the temporal configuration of the stimulus. Our data are inconsistent with this assumption.