An experimental study concerning visual localization in the horizontal plane.

Sharp, Werner L.

doi:10.1037/h0073349

Cited by 16 publications

(18 citation statements)

References 1 publication

(1 reference statement)

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“…Gi jV 1913; Matin, 1982Matin, , 1986McDougall, 1903;Nair, 1958;Sandstrom, 1951;Sharp, 1934;Stoper & Cohen, 1986), our results for the motionless in total darkness condition are between -3°and -4°below the true eye level, and around the mean value of -2.67°in the presence of the luminous frame. These data confirm the fact that the VPEL in the presence of a visual context is below the true eye level and above the VPEL in total darkness.…”

Section: Gi Ov3mentioning

confidence: 64%

“…The system that uses optical information from visible surfaces to determine the VPEL is called the "target/surface" system by Stoper and Cohen (1986). The role of visual information in determining the VPEL has been investigated mainly in studies comparing the presence versus the absence of visual cues (Hoppeler, 1913;Matin, 1982Matin, , 1986McDougall, 1903;Nair, 1958;Sandstrom, 1951;Sharp, 1934;Stoper & Cohen, 1986). Generally speaking, visual cues have been demonstrated to improve VPEL determination in relation to the true eye level; moreover, environmental visual cues significantly reduce the dispersion of VPEL settings in comparison with those obtained in darkness.…”

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confidence: 99%

“…Thus, when the observer states that an object appears to be above eye level, location is being specified relative to the norm VPEL that divides visually perceived space along a plane through the eyes, which is perceived to be perpendicular to the direction of gravity. In an upright position of the body, it has been demonstrated that this VPEL subjective reference is really perceived as being lower than the plane containing the true eye level (TEL)-that is, the physical eye level perpendicular to the direction of gravity ( Figure 1)-with constant errors of settings rarely exceeding 0.105 radians or 6° (McDougall, 1903;Sharp, 1934;Stoper & Cohen, 1986). Moreover, the settings relative to the true eye level are easier and more accurate in an illuminated environment than in darkness, in which only extraretinal, vestibular, and other proprioceptive information is available (Stoper & Cohen, 1986, 1991.…”

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confidence: 99%

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Effects of a visual frame and of low radial accelerations on the visually perceived eye level

Raphel

Barraud

Koessler

et al. 1996

Perception & Psychophysics

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Section: Gi Ov3mentioning

confidence: 64%

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confidence: 99%

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confidence: 99%

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Effects of a visual frame and of low radial accelerations on the visually perceived eye level

Raphel

Barraud

Koessler

et al. 1996

Perception & Psychophysics

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“…Although the subjective visual horizon was not recorded in the present experiment, the occurrence of such a phenomenon is clearly assumed in this study. Other previous works also reported that the subjective visual horizon is lower in darkness (Bringoux et al 2004(Bringoux et al , 2008MacDougall 1903;Raphel and Barraud 1994;Sharp 1934;Stoper and Cohen 1986). This phenomenon may be related to the 30°backward orientation of the saccular and utricular maculae relative to the head (Rosenhal 1972;Bortolami et al 2006).…”

Section: Discussionmentioning

confidence: 85%

Influence of gaze elevation on estimating the possibility of passing under high obstacles during body tilt

2008

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We investigated the influence of gaze elevation on judging the possibility of passing under high obstacles during pitch body tilts, while stationary, in absence of allocentric cues. Specifically, we aimed at studying the influence of egocentric references upon geocentric judgements. Seated subjects, orientated at various body orientations, were asked to perceptually estimate the possibility of passing under a projected horizontal line while keeping their gaze on a fixation target and imagining a horizontal body displacement. The results showed a global overestimation of the possibility of passing under the line, and confirmed the influence of body orientation reported by Bringoux et al. (Exp Brain Res 185(4):673-680, 2008). More strikingly, a linear influence of gaze elevation was found on perceptual estimates. Precisely, downward eye elevation yielded increased overestimations, and conversely upward gaze elevation yielded decreased overestimations. Furthermore, body and gaze orientation effects were independent and combined additively to yield a global egocentric influence with a weight of 45 and 54%, respectively. Overall, our data suggest that multiple egocentric references can jointly affect the estimated possibility of passing under high obstacles. These results are discussed in terms of ''interpenetrability'' between geocentric and egocentric reference frames and clearly demonstrate that gaze elevation is involved, as body orientation, in geocentric spatial localization.

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“…Observers in total darkness are typically able to set a target to VPEL with a precision ofless than 1°and an accuracy that deviates by no more than 5°from true eye level (Hoppeler, 1913;MacDougall, 1903;Matin & Fox, 1986Matin & Li, 1989a, 198%, 1990, 1991bMatin et a!., 1988;Matin et aI., 1982;Sharp, 1934;Stoper & Cohen, 1986. For VPEL settings in darkness to be other than randomly oriented, the controlling mechanism must make use of some combination of the neural signals regarding three sorts of information: extraretinal information about head orientation relative to gravity (EHOI), extraretinal eye position information relative to the head (EEPI), and information regarding retinal image position of the target used to set VPEL (Rl}.…”

Section: Levelmentioning

confidence: 99%

Light and dark adaptation of visually perceived eye level controlled by visual pitch

Matin

1995

Perception & Psychophysics

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The pitch of a visual field systematically influences the elevation at which a monocularly viewing subject sets a target so as to appear at visually perceived eye level (VPEL). The deviation of the setting from true eye level averages approximately 0.6 times the angle of pitch while viewing a fully illuminated complexly structured visual field and is only slightly less with one or two pitched-fromvertical lines in a dark field (Matin & Li, 1994a). The deviation of VPEL from baseline following 20 min of dark adaptation reaches its full value less than 1 min after the onset of illumination of the pitched visual field and decays exponentially in darkness following 5 min of exposure to visual pitch, either 30°topbackward or 20°topforward. The magnitude of the VPEL deviation measured with the dark-adapted right eye following left-eye exposure to pitch was 85%ofthe deviation that followed pitch exposure of the right eye itself. Time constants for VPEL decay to the dark baseline were the same for same-eye and cross-adaptation conditions and averaged about 4 min. The time constants for decay during dark adaptation were somewhat smaller, and the change during dark adaptation extended over a 16% smaller range following the viewing of the dim two-line pitched-from-vertical stimulus than following the viewing of the complex field. The temporal course of light and dark adaptation ofVPEL is virtually identical to the course oflight and dark adaptation of the scotopic luminance threshold following exposure to the same luminance. We suggest that, following rod stimulation along particular retinal orientations by portions of the pitched visual field, the storage of the adaptation process resides in the retinogeniculate system and is manifested in the focal system as a change in luminance threshold and in the ambient system as a change in VPEL.The linear model previously developed to account for VPEL, which was based on the interaction of influences from the pitched visual field and extraretinal influences from the body-referenced mechanism, was employed to incorporate the effects of adaptation. Connections between VPEL adaptation and other cases of perceptual adaptation of visual direction are described.The physical elevation of visually perceived eye level (VPEL) changes linearly with the pitch! of an illuminated visual field (Matin & Fox, 1986Matin, Fox, & Doktorsky, 1987;Matin & Li, 1989b, 1992b, 1992c, 1994a, 1994bMatin, Li, & Doktorsky, 1988;Stoper & Cohen, 1989). Employing the normally illuminated and complexly structured pitchroom shown in Figure 1a, average VPEL values for different groups of 8 subjects in two separate experiments deviated from true eye level by 0.61 and 0.63 times the angle of visual pitch over pitch ranges of 65°and 50°, respectively; one of the experiments involved monocular viewing, and the second involved binocular viewing. The slope of each subject's VPEL-versus-pitch function was linear, with individual slopes that ranged from +0.44 to +0.84. These individual slopes have demonstrated a great deal ...

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An experimental study concerning visual localization in the horizontal plane.

Cited by 16 publications

References 1 publication

Effects of a visual frame and of low radial accelerations on the visually perceived eye level

Effects of a visual frame and of low radial accelerations on the visually perceived eye level

Influence of gaze elevation on estimating the possibility of passing under high obstacles during body tilt

Light and dark adaptation of visually perceived eye level controlled by visual pitch

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