Object velocity relative to the head and depth order from object-produced motion parallax

ABSTRACTDiscerning objects from their surrounds (i.e., figure-ground segmentation) in a way that guides adaptive behaviours is a fundamental task of the brain. Neurophysiological work has revealed a class of cells in the macaque visual cortex that may be ideally suited to support this neural computation: border-ownership cells (Zhou, Friedman, & von der Heydt, 2000). These orientation-tuned cells appear to respond conditionally to the borders of objects. A behavioural correlate supporting the existence of these cells in humans was demonstrated using two-dimensional luminance defined objects (von der Heydt, Macuda, & Qiu, 2005). However, objects in our natural visual environments are often signalled by complex cues, such as motion and depth order. Thus, for border-ownership systems to effectively support figure-ground segmentation and object depth ordering, they must have access to information from multiple depth cues with strict depth order selectivity. Here we measure in humans (of both sexes) border-ownership-dependent tilt aftereffects after adapting to figures defined by either motion parallax or binocular disparity. We find that both depth cues produce a tilt aftereffect that is selective for figure-ground depth order. Further, we find the effects of adaptation are transferable between cues, suggesting that these systems may combine depth cues to reduce uncertainty (Bülthoff & Mallot, 1988). These results suggest that border-ownership mechanisms have strict depth order selectivity and access to multiple depth cues that are jointly encoded, providing compelling psychophysical support for their role in figure-ground segmentation in natural visual environments.SIGNIFICANCE STATEMENTSegmenting a visual object from its surrounds is a critical function that may be supported by “border-ownership” neural systems that conditionally respond to object borders. Psychophysical work indicates these systems are sensitive to objects defined by luminance contrast. To effectively support figure-ground segmentation, however, neural systems supporting border-ownership must have access to information from multiple depth cues and depth order selectivity. We measured border-ownership-dependent tilt aftereffects to figures defined by either motion parallax or binocular disparity and found aftereffects for both depth cues. These effects were transferable between cues, but selective for figure-ground depth order. Our results suggest that the neural systems supporting figure-ground segmentation have strict depth order selectivity and access to multiple depth cues that are jointly encoded.

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Dynamic Occlusion and Motion Parallax in Depth Perception

Perception ◽

10.1068/p170255 ◽

1988 ◽

Vol 17 (2) ◽

pp. 255-266 ◽

Cited By ~ 26

Author(s):

Hiroshi Ono ◽

Brian J Rogers ◽

Masao Ohmi ◽

Mika E Ono

Keyword(s):

Relative Motion ◽

Depth Perception ◽

Motion Parallax ◽

Three Dimensional ◽

Depth Order ◽

Depth Cues ◽

Small Depth ◽

Stationary Observer ◽

Depth Separation ◽

Condition B

Random-dot techniques were used to examine the interactions between the depth cues of dynamic occlusion and motion parallax in the perception of three-dimensional (3-D) structures, in two different situations: (a) when an observer moved laterally with respect to a rigid 3-D structure, and (b) when surfaces at different distances moved with respect to a stationary observer. In condition (a), the extent of accretion/deletion (dynamic occlusion) and the amount of relative motion (motion parallax) were both linked to the motion of the observer. When the two cues specified opposite, and therefore contradictory, depth orders, the perceived order in depth of the simulated surfaces was dependent on the magnitude of the depth separation. For small depth separations, motion parallax determined the perceived order, whereas for large separations it was determined by dynamic occlusion. In condition (b), where the motion parallax cues for depth order were inherently ambiguous, depth order was determined principally by the unambiguous occlusion information.

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Motion Parallax Information for Direction of Rotation in Depth: Order and Direction Components

Perception ◽

10.1068/p120559 ◽

1983 ◽

Vol 12 (5) ◽

pp. 559-569 ◽

Cited By ~ 1

Author(s):

David L Carpenter ◽

Michael P Dugan

Keyword(s):

College Students ◽

Motion Parallax ◽

Depth Order ◽

Motion In Depth ◽

The Status

The work of Hershberger and his associates has demonstrated the effectiveness for judging direction of rotation in depth of several components of motion parallax. Confounding and conflicting results have made the status of two of these transformations, labeled Direction and Order, unclear. A study is reported in which the problems encountered in previous studies have been eliminated. College students correctly judged the direction of rotation of horizontal rows of dots which appeared to rotate in depth, which demonstrates that Direction and Order can, in fact, provide useful information about direction of motion in depth.

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Head Movement Changes Apparent Depth Order in a Motion-Parallax Display

Perception ◽

10.1068/p220643 ◽

1993 ◽

Vol 22 (6) ◽

pp. 643-652 ◽

Cited By ~ 3

Author(s):

Keikichi Hayashibe

Keyword(s):

Head Movement ◽

Horizontal Plane ◽

Motion Parallax ◽

Apparent Depth ◽

Visual Depth ◽

Depth Order ◽

Direction Of Movement ◽

Random Dot Pattern ◽

Lateral Head

The hypothesis that the apparent visual depth is determined by the proximal velocity relative to the position of the head was examined in three experiments. Apparent protrusion/recession changed when subjects observed a moving random-dot pattern with their heads tilted sideways or rotated in the horizontal plane. This is ascribed to lateral head movement, which increases the proximal velocity when the dots and the subjects' heads are moving in opposite directions, and decreases the proximal velocity when both are moving in the same direction. Changes in the direction of movement of the stimulus caused a reversal of the apparent protrusion/recession. The resultant proximal velocity of the stimulus determined the order of depth of surfaces when the movement of the stimulus was linked to the subject's head movement.

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Border ownership-dependent tilt aftereffect for shape defined by binocular disparity and motion parallax

Journal of Neurophysiology ◽

10.1152/jn.00111.2019 ◽

2019 ◽

Vol 121 (5) ◽

pp. 1917-1923 ◽

Cited By ~ 1

Author(s):

Reuben Rideaux ◽

William J. Harrison

Keyword(s):

Binocular Disparity ◽

Motion Parallax ◽

Neural Systems ◽

Tilt Aftereffect ◽

Critical Function ◽

Depth Order ◽

Depth Cues ◽

Ground Segmentation ◽

Object Depth ◽

The Brain

Discerning objects from their surrounds (i.e., figure-ground segmentation) in a way that guides adaptive behaviors is a fundamental task of the brain. Neurophysiological work has revealed a class of cells in the macaque visual cortex that may be ideally suited to support this neural computation: border ownership cells (Zhou H, Friedman HS, von der Heydt R. J Neurosci 20: 6594–6611, 2000). These orientation-tuned cells appear to respond conditionally to the borders of objects. A behavioral correlate supporting the existence of these cells in humans was demonstrated with two-dimensional luminance-defined objects (von der Heydt R, Macuda T, Qiu FT. J Opt Soc Am A Opt Image Sci Vis 22: 2222–2229, 2005). However, objects in our natural visual environments are often signaled by complex cues, such as motion and binocular disparity. Thus for border ownership systems to effectively support figure-ground segmentation and object depth ordering, they must have access to information from multiple depth cues with strict depth order selectivity. Here we measured in humans (of both sexes) border ownership-dependent tilt aftereffects after adaptation to figures defined by either motion parallax or binocular disparity. We find that both depth cues produce a tilt aftereffect that is selective for figure-ground depth order. Furthermore, we find that the effects of adaptation are transferable between cues, suggesting that these systems may combine depth cues to reduce uncertainty (Bülthoff HH, Mallot HA. J Opt Soc Am A 5: 1749–1758, 1988). These results suggest that border ownership mechanisms have strict depth order selectivity and access to multiple depth cues that are jointly encoded, providing compelling psychophysical support for their role in figure-ground segmentation in natural visual environments. NEW & NOTEWORTHY Figure-ground segmentation is a critical function that may be supported by “border ownership” neural systems that conditionally respond to object borders. We measured border ownership-dependent tilt aftereffects to figures defined by motion parallax or binocular disparity and found aftereffects for both cues. These effects were transferable between cues but selective for figure-ground depth order, suggesting that the neural systems supporting figure-ground segmentation have strict depth order selectivity and access to multiple depth cues that are jointly encoded.

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