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A theory of moving form perception: Synergy between masking, perceptual grouping, and motion computation in retinotopic and non-retinotopic representations.

Oğmen H - Adv Cogn Psychol (2008)

Bottom Line: Based on this duration of visible persistence, we would expect moving objects to appear highly blurred.However, in human vision, objects in motion typically appear relatively sharp and clear.We suggest that clarity of form in dynamic viewing is achieved by a synergy between masking, perceptual grouping, and motion computation across retinotopic and non-retinotopic representations.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical & Computer Engineering, Center for Neuro-Engineering & Cognitive Science, University of Houston, Houston, TX 77204-4005 USA.

ABSTRACT
Because object and self-motion are ubiquitous in natural viewing conditions, understanding how the human visual system achieves a relatively clear perception for moving objects is a fundamental problem in visual perception. Several studies have shown that the visible persistence of a briefly presented stationary stimulus is approximately 120 ms under normal viewing conditions. Based on this duration of visible persistence, we would expect moving objects to appear highly blurred. However, in human vision, objects in motion typically appear relatively sharp and clear. We suggest that clarity of form in dynamic viewing is achieved by a synergy between masking, perceptual grouping, and motion computation across retinotopic and non-retinotopic representations. We also argue that dissociations observed in masking are essential to create and maintain this synergy.

No MeSH data available.


Related in: MedlinePlus

An example of a stimulus that leads to "amodal completion".						Typically, observers perceive a square behind the circle, even though part						of the square is not explicitly present in the image. This part is assumed						to be present and occluded by the circle.
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Figure 10: An example of a stimulus that leads to "amodal completion". Typically, observers perceive a square behind the circle, even though part of the square is not explicitly present in the image. This part is assumed to be present and occluded by the circle.

Mentions: When viewing the stimulus shown in Fig. 10, observers typically “perceive” a circle and a square even though part of the square is not directly visible. This type of figural completion is called amodal completion (Michotte, Thinès, & Crabbé, 1964). From a terminological point of view, to distinguish this type of perception from the perception that arises in response to “directly visible” stimulus, we use the term amodal visibility as opposed to phenomenal visibility. What is perceived behind the slit in anorthoscopic perception can be viewed as a dynamic version of amodal visibility. Even though all parts of the figure passing behind the slit are not simultaneously visible, observers “perceive” the complete shape. For example, after the tip of the triangle falls behind the occluder, observers continue to perceive the tip moving forward even though they do not directly see it. To accommodate this amodal effect, we simply assume that, at any given instant, the retinotopic and non-retinotopic activities that are linked by perceptual grouping (e.g., the tips of the triangle for t0, the middle parts of the triangles for t1, etc. in Fig. 9) become phenomenally visible. At any instant, the activity in the non-retinotopic space that has no correlated activity in the retinotopic space would be perceived “amodally”. We designate this as dynamic amodal perception in that the non-retinotopic activity without correlated retinotopic activity will appear to move according to the velocity vector associated with that part of the figure.


A theory of moving form perception: Synergy between masking, perceptual grouping, and motion computation in retinotopic and non-retinotopic representations.

Oğmen H - Adv Cogn Psychol (2008)

An example of a stimulus that leads to "amodal completion".						Typically, observers perceive a square behind the circle, even though part						of the square is not explicitly present in the image. This part is assumed						to be present and occluded by the circle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2864981&req=5

Figure 10: An example of a stimulus that leads to "amodal completion". Typically, observers perceive a square behind the circle, even though part of the square is not explicitly present in the image. This part is assumed to be present and occluded by the circle.
Mentions: When viewing the stimulus shown in Fig. 10, observers typically “perceive” a circle and a square even though part of the square is not directly visible. This type of figural completion is called amodal completion (Michotte, Thinès, & Crabbé, 1964). From a terminological point of view, to distinguish this type of perception from the perception that arises in response to “directly visible” stimulus, we use the term amodal visibility as opposed to phenomenal visibility. What is perceived behind the slit in anorthoscopic perception can be viewed as a dynamic version of amodal visibility. Even though all parts of the figure passing behind the slit are not simultaneously visible, observers “perceive” the complete shape. For example, after the tip of the triangle falls behind the occluder, observers continue to perceive the tip moving forward even though they do not directly see it. To accommodate this amodal effect, we simply assume that, at any given instant, the retinotopic and non-retinotopic activities that are linked by perceptual grouping (e.g., the tips of the triangle for t0, the middle parts of the triangles for t1, etc. in Fig. 9) become phenomenally visible. At any instant, the activity in the non-retinotopic space that has no correlated activity in the retinotopic space would be perceived “amodally”. We designate this as dynamic amodal perception in that the non-retinotopic activity without correlated retinotopic activity will appear to move according to the velocity vector associated with that part of the figure.

Bottom Line: Based on this duration of visible persistence, we would expect moving objects to appear highly blurred.However, in human vision, objects in motion typically appear relatively sharp and clear.We suggest that clarity of form in dynamic viewing is achieved by a synergy between masking, perceptual grouping, and motion computation across retinotopic and non-retinotopic representations.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical & Computer Engineering, Center for Neuro-Engineering & Cognitive Science, University of Houston, Houston, TX 77204-4005 USA.

ABSTRACT
Because object and self-motion are ubiquitous in natural viewing conditions, understanding how the human visual system achieves a relatively clear perception for moving objects is a fundamental problem in visual perception. Several studies have shown that the visible persistence of a briefly presented stationary stimulus is approximately 120 ms under normal viewing conditions. Based on this duration of visible persistence, we would expect moving objects to appear highly blurred. However, in human vision, objects in motion typically appear relatively sharp and clear. We suggest that clarity of form in dynamic viewing is achieved by a synergy between masking, perceptual grouping, and motion computation across retinotopic and non-retinotopic representations. We also argue that dissociations observed in masking are essential to create and maintain this synergy.

No MeSH data available.


Related in: MedlinePlus