Conference article

Illusory motion; in which observers can perceive static images to be moving; is an important graphic design concept. Although the mechanism of illusory motion is being uncovered; it is still unclear whether illusory motion can induce postural sway. Patients with migraine headaches (migraineurs) are likely to suffer from motion sickness and are more likely to perceive illusory motion than are individuals without chronic headaches. Since one of the causes of motion sickness is the conflict between visual and vestibular inputs; we hypothesized that migraineurs have an abnormal visuo-vestibular interaction. We measured postural sway during migraineurs’ and normal controls’ viewing of static visual stimuli with and without illusory motion. We used Kitaoka’s artworks as both the illusory motion and control stimuli (Kitaoka; 2003; 2013). The participants stood on a stabilometer while they viewed one stimulus for 30 seconds. Immediately afterward (Experiment 1); or 30 seconds after viewing the stimuli (Experiment 2); the participants closed their eyes and stood on the stabilometer for 30 seconds. The results from Experiment 1 indicated that migraineurs swayed more than controls while their eyes were closed after viewing the illusory motion image. However; in Experiment 2; migraineurs swayed less than controls with their eyes closed following a 30-second interval after viewing the illusory motion. Taken together; these results suggest that static visual stimuli induce not only illusory motion but also postural sway; which may last for 30 seconds in migraineurs.

Illusory Motion; Vision; Migraine; Postural Sway