Visual contribution to postural stability: Interaction between target fixation or tracking and static or dynamic large-field stimulus

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• 作者：J. Laurens ; L. Awai ; C.J. Bockisch ; S. Hegemann ; H.J.A. van Hedel ; V. Dietz ; D. Straumann
• 关键词：Posture ; Body sway ; Vision ; Retinal flow ; Eye movements
• 刊名：Gait and Posture
• 出版年：2010
• 出版时间：January 2010
• 年：2010
• 卷：31
• 期：1
• 页码：37-41
• 全文大小：473 K

文摘

Stationary visual information has a stabilizing effect on posture, whereas moving visual information is destabilizing. We compared the influence of a stationary or moving fixation point to the influence of stationary or moving large-field stimulation, as well as the interaction between a fixation point and a large-field stimulus. We recorded body sway in 20 healthy subjects who were fixating a stationary or oscillating dot (vertical or horizontal motion, 1/3 Hz, ±12° amplitude, distance 96 cm). In addition, a large-field random dot pattern (extension: 80 × 70°) was stationary, moving or absent. Visual fixation of a stationary dot in darkness did not reduce antero-posterior (AP) sway compared to the situation in total darkness, but slightly reduced lateral sway at frequencies below 0.5 Hz. In contrast, fixating a stationary dot on a stationary large-field pattern reduced both AP and lateral body sway at all frequencies (0.1–2 Hz). Ocular tracking of the oscillating dot caused a peak in body sway at 1/3 Hz, i.e. the stimulus frequency, but there was no influence of large-field stimulus at this frequency. A stationary large-field pattern, however, reduced AP and lateral sway at frequencies between 0.1 and 2 Hz when subjects tracked a moving dot, compared to tracking in darkness. Our results demonstrate that a stationary large-field pattern has a stabilizing effect in all conditions, independent of whether the eyes are fixing on a stationary target or tracking a moving target.