Distance impairs postural stability only under binocular viewing
Autor: | Zoï Kapoula, Thanh-Thuan Lê |
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Rok vydání: | 2006 |
Předmět: |
Adult
Aging medicine.medical_specialty genetic structures Visual Acuity Postural stability Audiology Binocular and monocular viewing Standard deviation Optics Psychophysics medicine Humans Postural Balance Vision Binocular Monocular Distance business.industry Distance Perception Convergence Ocular Middle Aged eye diseases Sensory Systems Ageing Ophthalmology Fixation (visual) Binocular disparity business Psychology Monocular vision Binocular vision |
Zdroj: | Vision Research. 46(21):3586-3593 |
ISSN: | 0042-6989 |
DOI: | 10.1016/j.visres.2006.06.018 |
Popis: | Prior studies indicate that postural stability under binocular viewing is not better than under monocular viewing. This was tested at the distances of 145 cm [Fox, C.R. (1990). Some visual influences on human postural equilibrium: binocular versus monocular fixation. Perception and Psychophysics, 47 (5), 409–422] and 90 cm [Isotalo, E., Kapoula, Z., Feret, P.H., Gauchon, K., Zamfirescu, F., & Gagey, P.M. (2004). Monocular versus binocular vision in postural control. Auris Nasus Larynx, 31 (1), 11–17]. On the other hand, postural stability is known to decrease with distance increase. We re-examined the effect of binocular versus monocular viewing on postural stability at near and far distances (40 and 200 cm), and for both young (25.7 ± 2.7 years), and old subjects (61.2 ± 4.6 years). For both groups of subjects, proximity decreased the area of CoP, the standard deviation of antero-posterior sway (SDy) and the variance of speed. The group of elderly presented increased variance of speed at far distance in comparison with young subjects. The novel finding is the interaction between distance and viewing condition. Under binocular viewing, the area of CoP was significantly higher at far distance than at near; in contrast, monocular viewing produced similar CoP values at both distances. Increased instability at far distance when both eyes are viewing is attributed to decreased sensitivity to binocular disparity cues and to visual motion in depth resulting from body sway. Monocular viewing would provide similar stability at far and at near distance, because sensitivity to lateral visual motion, detected monocularly, decreases less with distance than sensitivity to binocularly detected motion in depth. Alternatively, such monocular viewing could increase subject’s attention and lead to tighter postural control regardless of the distance. |
Databáze: | OpenAIRE |
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