Relationship between Stability of Subjective Straight Ahead and Effect of Gaze on Body Sway Direction Induced by Neck Dorsal Muscles Stimulation

Abstract

Previous studies have reported that gaze influences on body sway direction induced by neck dorsal muscle stimulation (NS) and that the strength of the gaze influence differs from a subject to another. In the present study, to investigate the reason for the difference, we analyzed a relationship between the strength of the gaze influence and the stability of subjective straight ahead. Seventeen subjects participated in the following two sets of measurements. First, the direction of body sway induced by NS was measured at different gaze orientations. Then, subjective straight ahead was measured. Depending on the strength of the influence, the subjects were classified into two groups. Five subjects were deemed to have strong gaze influence while the other twelve showed weak influence. A comparison between the two groups revealed a significant difference in the stability of the measured subjective straight ahead, suggesting a relationship between the strength of the gaze influence and the stability of the subjective straight ahead.