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Perceived self-orientation in allocentric and egocentric space: effects of visual and physical tilt on saccadic and tactile measures.
Brain Res. 2008 Nov 25; 1242:231-43.BR

Abstract

Do physical tilt and tilt of the visual environment affect perception of allocentric and egocentric space? We addressed this question using two perceptual-motor tasks: alignment of a tactile rod (ROD) and saccadic eye movements (EM). Nine participants indicated the vertical axis of their heads (egocentric task), as well as the direction of gravity (allocentric task). Head orientation (+/-60 degrees and 0 degrees) and visual environment orientation (+/-120 degrees, +/-60 degrees and 0 degrees) were independently manipulated in the fronto-planar roll plane. ROD and EM estimates of both allocentric and egocentric reference directions varied with head and room orientation. Physical tilt dominated allocentric estimates in the dark where overestimates of physical tilt were noted up to 11 degrees using both measures. Allocentric ROD and EM estimates were significantly correlated across all head orientations (r=.70, p<.01) but only when upright for egocentric estimates (r=.38, p<.01). The relative contributions of the visual environment, gravity's direction and long-body axis to the estimation of allocentric and egocentric directions were determined by vector modeling. This modeling found that vision determined about 14% of the allocentric ROD and EM estimates, that the long-axis body reference played no discernible role, and that the largest factor was gravity, the effective direction of which was non-veridical. For egocentric estimates, vision contributed about 3% with the largest factor being the body reference. We conclude that perception of allocentric and egocentric space is likely influenced by multiple senses that define common egocentric and allocentric frames of reference accessible for saccadic and tactile estimates of perceived self-orientation.

Authors+Show Affiliations

Multisensory Integration Laboratory, Centre for Vision Research, Department of Psychology, York University, 4700 Keele Street, Toronto, Ontario, Canada. mikebc@yorku.caNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

18706895

Citation

Barnett-Cowan, Michael, and Laurence R. Harris. "Perceived Self-orientation in Allocentric and Egocentric Space: Effects of Visual and Physical Tilt On Saccadic and Tactile Measures." Brain Research, vol. 1242, 2008, pp. 231-43.
Barnett-Cowan M, Harris LR. Perceived self-orientation in allocentric and egocentric space: effects of visual and physical tilt on saccadic and tactile measures. Brain Res. 2008;1242:231-43.
Barnett-Cowan, M., & Harris, L. R. (2008). Perceived self-orientation in allocentric and egocentric space: effects of visual and physical tilt on saccadic and tactile measures. Brain Research, 1242, 231-43. https://doi.org/10.1016/j.brainres.2008.07.075
Barnett-Cowan M, Harris LR. Perceived Self-orientation in Allocentric and Egocentric Space: Effects of Visual and Physical Tilt On Saccadic and Tactile Measures. Brain Res. 2008 Nov 25;1242:231-43. PubMed PMID: 18706895.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Perceived self-orientation in allocentric and egocentric space: effects of visual and physical tilt on saccadic and tactile measures. AU - Barnett-Cowan,Michael, AU - Harris,Laurence R, Y1 - 2008/07/29/ PY - 2008/01/31/received PY - 2008/07/11/revised PY - 2008/07/12/accepted PY - 2008/8/19/pubmed PY - 2009/2/10/medline PY - 2008/8/19/entrez SP - 231 EP - 43 JF - Brain research JO - Brain Res. VL - 1242 N2 - Do physical tilt and tilt of the visual environment affect perception of allocentric and egocentric space? We addressed this question using two perceptual-motor tasks: alignment of a tactile rod (ROD) and saccadic eye movements (EM). Nine participants indicated the vertical axis of their heads (egocentric task), as well as the direction of gravity (allocentric task). Head orientation (+/-60 degrees and 0 degrees) and visual environment orientation (+/-120 degrees, +/-60 degrees and 0 degrees) were independently manipulated in the fronto-planar roll plane. ROD and EM estimates of both allocentric and egocentric reference directions varied with head and room orientation. Physical tilt dominated allocentric estimates in the dark where overestimates of physical tilt were noted up to 11 degrees using both measures. Allocentric ROD and EM estimates were significantly correlated across all head orientations (r=.70, p<.01) but only when upright for egocentric estimates (r=.38, p<.01). The relative contributions of the visual environment, gravity's direction and long-body axis to the estimation of allocentric and egocentric directions were determined by vector modeling. This modeling found that vision determined about 14% of the allocentric ROD and EM estimates, that the long-axis body reference played no discernible role, and that the largest factor was gravity, the effective direction of which was non-veridical. For egocentric estimates, vision contributed about 3% with the largest factor being the body reference. We conclude that perception of allocentric and egocentric space is likely influenced by multiple senses that define common egocentric and allocentric frames of reference accessible for saccadic and tactile estimates of perceived self-orientation. SN - 1872-6240 UR - https://www.unboundmedicine.com/medline/citation/18706895/Perceived_self_orientation_in_allocentric_and_egocentric_space:_effects_of_visual_and_physical_tilt_on_saccadic_and_tactile_measures_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-8993(08)01759-9 DB - PRIME DP - Unbound Medicine ER -