The role of head-centric spatial reference with a static and kinetic visual disturbance.
A static or kinetic visual disturbance affects subjects' ability to estimate the direction of the gravitational vertical. This kind of error is increased by a head roll inclination. In two experiments, we combined head orientation with a static (Experiment 1: tilted frame) versus kinetic (Experiment 2: rotating disk) visual disturbance. The results showed that with a static visual disturbance, the increase of errors in the inclined head condition was mainly the consequence of a postural head effect like an Aubert effect. On the contrary, with a kinetic visual disturbance, it appears that the disk effect increases with head inclination. However, individual errors observed with the head inclined in front of a stationary disk were systematically correlated with the errors triggered by the same head inclination in front of a rotating disk. These observations confirm that the head axis spatial reference plays an important role in orientation perception, whatever the head position and the kind of visual display.
Guerraz
M
M
Université Pierre Mendès France, Grenoble, France.
Poquin
D
D
Ohlmann
T
T
D000293:Adolescent; D000328:Adult; D001288:Attention; D003623:Dark Adaptation; D005260:Female; D006112:Gravitation; D019416:Head Movements; D006801:Humans; D007699:Kinesthesis; D008297:Male; D009039:Motion Perception; D009903:Optical Illusions; D009949:Orientation; D010364:Pattern Recognition, Visual; D011187:Posture; D011597:Psychomotor Performance; D011601:Psychophysics; D012737:Sex Factors