Bloomberg JJ, Reschke MF, Peters BT, Huebner WP.

Abstr Soc Neurosci. 1991; 17: 318.

Space Biomedical Research Institute, NASA Johnson Space Center, Houston, TX.

Berthoz and Pozzo (1988) have suggested that gait motor programs operate in a "top-down" fashion to preserve gaze stability during locomotion. To further investigate this hypothesis we had three subjects walk (6.4 km/h) on a motorized treadmill while visually fixating an earth-fixed target positioned in the center of view either near (30 cm) or far (2 m) from the head. Head movements were recorded using a video-based motion analysis system. During gaze fixation of both near and far targets, pitch head movements were compensatory for linear Z-axis head motion. The mean peak to peak amplitude of compensatory pitch head movements for all 3 subjects increased from 2.24 +/- 0.07 degrees (mean +/- S.E.) in the far target condition to 3.31 +/- 0.22 degrees in the near target condition, despite no significant change in mean peak to peak linear Z-axis head motion (3.03 +/- 0.77 cm, far and 2.99 +/- 0.82 cm, near). This result confirms that compensatory pitch head movements are driven by the need to stabilize gaze during locomotion. This stabilization is achieved through a synergistic combination of goal-directed eye and head movements. Gait instabilities experienced by astronauts upon the return to Earth may be caused by in-flight adaptive acquisition of new motor strategies designed to maintain head and gaze stable in microgravity, but may be inappropriate for a terrestrial environment.

Publication Types:

• Meeting Abstracts

Keywords:

• Astronauts
• Fixation, Ocular
• Gait
• Head
• Head Movements
• Locomotion
• Walking
• NASA Center JSC
• NASA Discipline Neuroscience
• NASA Discipline Number 16-10
• NASA Program Space Physiology and Countermeasures

Other ID:

• 95607692

UI: 102212633

From Meeting Abstracts