The role of binocular vision in prehension: a kinematic analysis

Servos, Philip; Goodale, Melvyn A.; Jakobson, Lorna S.

doi:10.1016/0042-6989(92)90207-y

Cited by 223 publications

(161 citation statements)

References 31 publications

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“…This result, combined with earlier observations in normal subjects (Servos et al 1992), suggests that binocular information plays a critical role in normal human prehension. When calibrating the grasp, information about distance derived from stereo and/or convergence is combined with information from the size of the retinal image of the goal object (which will vary systematically with viewing distance).…”

Section: Discussionsupporting

confidence: 81%

“…4 shows, both DF and JW, like the control subjects and like subjects in earlier experiments (e.g. Servos et al 1992), showed a systematic increase in velocity with object distance under both viewing conditions. In short, distance scaling for reach kinematics in DF and JW, unlike grip calibration, seemed rather refractory to the removal of binocular information.…”

Section: Resultssupporting

confidence: 60%

“…3 shows, duration increased with increased object distance in DF and her three control subjects under both binocular and monocular viewing conditions. Moreover, as Servos et al (1992) originally observed, there was a tendency for movement durations to be longer when only monocular cues were available. Although JW showed a similar increase in movement duration with object distance under both binocular and monocular viewing conditions, the typical increase in movement duration with monocular viewing was not observed.…”

Section: Resultssupporting

confidence: 55%

“…Servos et al (1992) demonstrated that grasping movements made under monocular viewing were less 'efficient' than those performed under binocular viewing conditions, achieving lower peak velocities and showing prolonged periods of deceleration during the closing phase of the grasp. But even though this shows that binocular information plays a significant role in prehension, the subjects were still able to pick up the goal objects with little difficulty when binocular vision was denied, suggesting that the available monocular cues were sufficient to calibrate their grasp.…”

Section: Introductionmentioning

confidence: 96%

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The removal of binocular cues disrupts the calibration of grasping in patients with visual form agnosia

1997

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The present study tested the idea that the visuomotor systems mediating prehension do not have independent access to pictorial cues processed by perceptual mechanisms. Individuals with visual form agnosia, whose perceptual systems are compromised but who have intact visuomotor control, were examined to determine whether they could use pictorial scene cues to calibrate manual prehension when binocular information was removed. The removal of binocular cues produced considerable disruptions in size-constancy of grip aperture, which, combined with earlier observations in normal subjects, suggests that binocular cues are of primary importance in calibration of grasping. In the absence of binocular vision, normal subjects can use pictorial information, information that is severely compromised in individuals with visual form agnosia, to compute the distance (and thus the size) of the goal object. Thus, individuals with visual form agnosia must rely on a retinal image that remains uncalibrated, leading to inaccurate calibrations of grip aperture. The fact that these individuals scaled their grasp much less accurately under the monocular viewing condition, despite showing normal binocular grasping, suggests that pictorial cues to depth, which are presumably processed by mechanisms mediating our perception of objects and events in the world, can be accessed by visuomotor mechanisms only indirectly. These results, together with others, suggest that the visuomotor system 'prefers' to use binocular information and uses pictorial cues only as a last resort.

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Section: Discussionsupporting

confidence: 81%

Section: Resultssupporting

confidence: 60%

Section: Resultssupporting

confidence: 55%

Section: Introductionmentioning

confidence: 96%

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The removal of binocular cues disrupts the calibration of grasping in patients with visual form agnosia

1997

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“…Such cues are often considered to be particularly involved in the control of action tasks as, in principle, they provide accurate metric 3-D information about the world (Servos et al 1992;Dijkerman et al 1996;Jackson et al 1997;Marotta et al 1997;Watt and Bradshaw 2000). The use of binocular cues for the control of action is supported by the fact that binocular depth processing is associated with activity in areas V3A and MT (DeAngelis et al 1998;Backus et al 2001), regions with clear connections with the parietal areas (Lennie 1998).…”

mentioning

confidence: 99%

2-D Tilt and 3-D Slant Illusions in Perception and Action Tasks

Hibbard

Bradshaw

2006

Perception

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There is now a well established dissociation between perception and action based primarily on neuropsychological evidence [Milner and Goodale, 1995 The Visual Brain in Action (Oxford: Oxford University Press)]. Although equivocal, an important source of evidence from normal observers is that ‘perceptual illusions’ may affect the systems differently. We investigated the relative effects of 2-D tilt and 3-D slant illusions in the two domains, using similar tasks to those employed originally by Milner and Goodale. Subjects were required to either post a card through, or set a paddle to match the orientation of, a plane that was presented in two conditions: surrounded by a striped surface tilted between +90° and −90° (2-D tilt contrast), or surrounded by a disparity defined surface slanted in depth between +60° and −60° (3-D depth contrast). For 2-D tilt, action and perception were equally affected by the illusion, whereas in the 3-D condition they were not. Here, the illusion appeared greater in the posting than in the perceptual task. We conclude that, although no qualitative differences exist, there were quantitative differences between perception and action tasks in the binocular condition.

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Tangible, Dynamic Holographic Images

Plesniak

Pappu

Benton

2002

Three‐Dimensional Holographic Imaging

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Good holograms are bewitching. They command our eyes to their images, to search the marvelous realness of surfaces, textures, and minute detail for some aberration, some visual clue that will dissuade us from seeing as real what we know is not. Yet while they seem to assemble the very molecules of physical matter for us to ponder, they also present a conundrum: The objects they render appear frozen, lifeless, and confounding to our fingertips.What if we could render these images animate and touchable, as phantom material that was both dynamic and plastic? Such an ultimate display would be both powerful and magical; it would deliver naturally to our spatial proficiencies, inspire our imaginations, and perhaps even provoke our emotions. Of course, such a display does not yet exist, and many challenges to its development remain. But while current technology still leaves us in the shadow of such a goal, we are beginning to see it as more real than chimerical.To this end, we will describe our first experiments with tangible, dynamic holographic images. Our prototype system, called the holo-haptic system, comprises a sizeable arsenal of computers and both commercial and custom hardware. The visual images it produces for these experiments are monochromatic, postcard-sized, and depict only simple geometries. The haptic images it produces are felt and shaped with a hand-held device. Thus, the trappings of engineering are anything but transparent to the experience, and the demonstrations themselves are artistically unsophisticated. But by using this agglomeration of technology in simple demonstrations, we can feel and sculpt threedimensional shapes made only of light -which inches us closer to where we want to go.

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The role of binocular vision in prehension: a kinematic analysis

Cited by 223 publications

References 31 publications

The removal of binocular cues disrupts the calibration of grasping in patients with visual form agnosia

The removal of binocular cues disrupts the calibration of grasping in patients with visual form agnosia

2-D Tilt and 3-D Slant Illusions in Perception and Action Tasks

Tangible, Dynamic Holographic Images

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