Easton R D, Greene A J, DiZio P, Lackner J R
Boston College, Department of Psychology, Chestnut Hill, MA 02167, USA.
Exp Brain Res. 1998 Feb;118(4):541-50. doi: 10.1007/s002210050310.
This study assessed whether stationary auditory information could affect body and head sway (as does visual and haptic information) in sighted and congenitally blind people. Two speakers, one placed adjacent to each ear, significantly stabilized center-of-foot-pressure sway in a tandem Romberg stance, while neither a single speaker in front of subjects nor a head-mounted sonar device reduced center-of-pressure sway. Center-of-pressure sway was reduced to the same level in the two-speaker condition for sighted and blind subjects. Both groups also evidenced reduced head sway in the two-speaker condition, although blind subjects' head sway was significantly larger than that of sighted subjects. The advantage of the two-speaker condition was probably attributable to the nature of distance compared with directional auditory information. The results rule out a deficit model of spatial hearing in blind people and are consistent with one version of a compensation model. Analysis of maximum cross-correlations between center-of-pressure and head sway, and associated time lags suggest that blind and sighted people may use different sensorimotor strategies to achieve stability.
本研究评估了固定的听觉信息是否会像视觉和触觉信息那样，影响有视力者和先天性盲人的身体及头部晃动。两个扬声器，分别置于每只耳朵附近，显著稳定了串联罗姆伯格姿势下的足底压力中心晃动，而受试者前方的单个扬声器或头戴式声纳设备均未降低压力中心晃动。在双扬声器条件下，有视力者和盲人的压力中心晃动均降低到相同水平。两组在双扬声器条件下头部晃动也均有所减少，不过盲人的头部晃动明显大于有视力者。双扬声器条件的优势可能归因于与定向听觉信息相比的距离特性。研究结果排除了盲人空间听觉缺陷模型，与一种补偿模型的版本相符。对压力中心与头部晃动之间的最大互相关及相关时间滞后的分析表明，盲人和有视力者可能采用不同的感觉运动策略来实现稳定性。
