Effects of Proprioceptive Processing on the Illusory Flash-Lag Effect in Motion and Luminance Change

Abstract

Observer's active control of visual stimulus movement by the use of computer mouse reduces the flash-lag effect (Ichikawa & Masakura, 2006, Vision Research). This reduction of the flash-lag effect in visual motion depends upon directional relationship between hand movement and visual stimulus movement (Ichikawa & Masakura, 2010 AP&P). These studies indicate that the reduction of the flash-lag effect depends upon the sensory-motor learning of the directional consistency between the hand movement and stimulus movement in everyday-computer use. In this study, we examined how directional relationship between hand movement and stimulus change, which is not involved in every-computer use, affects the reduction of the flash-lag effect if there is no inevitable directional relationship between hand movement and stimulus change. While the luminance of the visual stimulus was controlled by the use of computer-mouse, a flash was presented. Observer judged which of the flash and luminance change stimulus is lighter. We found significant reduction of the flash-lag effect only when the directional relationship between hand movement and stimulus change was fixed. The results suggest that the proprioceptive signal to control the visual stimulus would facilitate the visual processing if the directional relationship between hand movement and stimulus change is consistent.