Jeka J J, Easton R D, Bentzen B L, Lackner J R
Brandeis University, Waltham, Massachusetts, USA.
Percept Psychophys. 1996 Apr;58(3):409-23. doi: 10.3758/bf03206817.
Haptic cues from fingertip contact with a stable surface attenuate body sway in subjects even when the contact forces are too small to provide physical support of the body. We investigated how haptic cues derived from contact of a cane with a stationary surface at low force levels aids postural control in sighted and congenitally blind individuals. Five sighted (eyes closed) and five congenitally blind subjects maintained a tandem Romberg stance in five conditions: (1) no cane; (2,3) touch contact (< 2 N of applied force) while holding the cane in a vertical or slanted orientation; and (4,5) force contact (as much force as desired) in the vertical and slanted orientations. Touch contact of a cane at force levels below those necessary to provide significant physical stabilization was as effective as force contact in reducing postural sway in all subjects, compared to the no-cane condition. A slanted cane was far more effective in reducing postural sway than was a perpendicular cane. Cane use also decreased head displacement of sighted subjects far more than that of blind subjects. These results suggest that head movement control is linked to postural control through gaze stabilization reflexes in sighted subjects; such reflexes are absent in congenitally blind individuals and may account for their higher levels of head displacement.
即使接触力小到无法为身体提供物理支撑，指尖与稳定表面接触产生的触觉线索也会减弱受试者的身体摇摆。我们研究了在低力水平下，手杖与固定表面接触产生的触觉线索如何帮助有视力者和先天性盲人进行姿势控制。五名有视力者（闭眼）和五名先天性盲人在五种条件下保持串联罗姆伯格姿势：（1）不使用手杖；（2,3）手持手杖垂直或倾斜时进行触摸接触（施加力<2N）；以及（4,5）在垂直和倾斜方向上进行力接触（所需的任意力）。与不使用手杖的情况相比，在所有受试者中，力水平低于提供显著物理稳定所需水平的手杖触摸接触在减少姿势摇摆方面与力接触同样有效。倾斜的手杖在减少姿势摇摆方面比垂直的手杖有效得多。使用手杖也使有视力者的头部位移减少幅度远大于盲人受试者。这些结果表明，在有视力者中，头部运动控制通过注视稳定反射与姿势控制相关联；先天性盲人个体缺乏这种反射，这可能是他们头部位移水平较高的原因。
