PDF(Pubmed)
Abstract：
UNASSIGNED: Previous experiments purportedly showed that image-based factors like convexity were sufficient for figure assignment. Recently, however, we found that the probability of perceiving a figure on the convex side of a central border was only slightly higher than chance for two-region displays and increased with the number of display regions; this increase was observed only when the concave regions were homogeneously colored. These convex figure context effects (CEs) revealed that figure assignment in these classic displays entails more than a response to local convexity. A Bayesian observer replicated the convex figure CEs using both a convexity object prior and a new, homogeneous background prior and made the novel prediction that the classic displays in which both the convex and concave regions were homogeneous were ambiguous during perceptual organization.
UNASSIGNED: Here, we report three experiments investigating the proposed ambiguity and examining how the convex figure CEs unfold over time with an emphasis on whether they entail recurrent processing. Displays were shown for 100 ms followed by pattern masks after ISIs of 0, 50, or 100 ms. The masking conditions were designed to add noise to recurrent processing and therefore to delay the outcome of processes in which they play a role. In Exp. 1, participants viewed two- and eight-region displays with homogeneous convex regions (homo-convex displays; the putatively ambiguous displays). In Exp. 2, participants viewed putatively unambiguous hetero-convex displays. In Exp. 3, displays and masks were presented to different eyes, thereby delaying mask interference in the thalamus for up to 100 ms.
UNASSIGNED: The results of Exps. 1 and 2 are consistent with the interpretation that recurrent processing is involved in generating the convex figure CEs and resolving the ambiguity of homo-convex displays. The results of Exp. 3 suggested that corticofugal recurrent processing is involved in resolving the ambiguity of homo-convex displays and that cortico-cortical recurrent processes play a role in generating convex figure CEs and these two types of recurrent processes operate in parallel. Our results add to evidence that perceptual organization evolves dynamically and reveal that stimuli that seem unambiguous can be ambiguous during perceptual organization.
UNASSIGNED: Here, we report three experiments investigating the proposed ambiguity and examining how the convex figure CEs unfold over time with an emphasis on whether they entail recurrent processing. Displays were shown for 100 ms followed by pattern masks after ISIs of 0, 50, or 100 ms. The masking conditions were designed to add noise to recurrent processing and therefore to delay the outcome of processes in which they play a role. In Exp. 1, participants viewed two- and eight-region displays with homogeneous convex regions (homo-convex displays; the putatively ambiguous displays). In Exp. 2, participants viewed putatively unambiguous hetero-convex displays. In Exp. 3, displays and masks were presented to different eyes, thereby delaying mask interference in the thalamus for up to 100 ms.
UNASSIGNED: The results of Exps. 1 and 2 are consistent with the interpretation that recurrent processing is involved in generating the convex figure CEs and resolving the ambiguity of homo-convex displays. The results of Exp. 3 suggested that corticofugal recurrent processing is involved in resolving the ambiguity of homo-convex displays and that cortico-cortical recurrent processes play a role in generating convex figure CEs and these two types of recurrent processes operate in parallel. Our results add to evidence that perceptual organization evolves dynamically and reveal that stimuli that seem unambiguous can be ambiguous during perceptual organization.
摘要：
■先前的实验据称表明，基于图像的因素，如凸性足以进行图形分配。最近,然而,我们发现，在中央边界的凸面上感知图形的可能性仅略高于两个区域显示的机会，并且随着显示区域的数量而增加；只有在凹面区域颜色均匀时才观察到这种增加。这些凸图形上下文效应（CE）表明，这些经典显示中的图形分配不仅需要对局部凸性的响应。贝叶斯观察者使用凸性对象先验和新的，同质背景先验，并做出了新颖的预测，即在感知组织过程中，凸区域和凹区域都是同质的经典显示是模糊的。
■这里，我们报告了三个实验，调查了所提出的歧义，并研究了凸图形CE如何随着时间的推移而展开，重点是它们是否需要重复处理。显示时间为100毫秒，然后显示ISI为0、50或100毫秒后的图案掩模。掩蔽条件被设计为向重复处理添加噪声,并且因此延迟它们在其中发挥作用的过程的结果。在Exp中。在图1中，参与者观看了具有均匀凸区域的两个和八个区域显示（同凸显示；假定的模糊显示）。在Exp中。2，参与者观看了推定的明确的异凸显示。在Exp中。3，显示器和面具被呈现给不同的眼睛，从而延迟丘脑中的掩模干扰达100毫秒。
■Exps的结果。图1和图2与以下解释一致：在生成凸图CE并解决同凸显示的歧义时涉及循环处理。Exp的结果。3表明，皮质-皮质循环过程涉及解决同凸显示的歧义，皮质-皮质循环过程在生成凸图CE中起作用，这两种类型的循环过程并行运行。我们的结果增加了知觉组织动态发展的证据，并揭示了在知觉组织过程中看似明确的刺激可能是模糊的。
■这里，我们报告了三个实验，调查了所提出的歧义，并研究了凸图形CE如何随着时间的推移而展开，重点是它们是否需要重复处理。显示时间为100毫秒，然后显示ISI为0、50或100毫秒后的图案掩模。掩蔽条件被设计为向重复处理添加噪声,并且因此延迟它们在其中发挥作用的过程的结果。在Exp中。在图1中，参与者观看了具有均匀凸区域的两个和八个区域显示（同凸显示；假定的模糊显示）。在Exp中。2，参与者观看了推定的明确的异凸显示。在Exp中。3，显示器和面具被呈现给不同的眼睛，从而延迟丘脑中的掩模干扰达100毫秒。
■Exps的结果。图1和图2与以下解释一致：在生成凸图CE并解决同凸显示的歧义时涉及循环处理。Exp的结果。3表明，皮质-皮质循环过程涉及解决同凸显示的歧义，皮质-皮质循环过程在生成凸图CE中起作用，这两种类型的循环过程并行运行。我们的结果增加了知觉组织动态发展的证据，并揭示了在知觉组织过程中看似明确的刺激可能是模糊的。
