A slowly moving foreground can capture an observer's self-motion - a report of a new motion illusion: inverted vection

We investigated interactions between foreground and background stimuli duri ng visually induced perception of self-motion (vection) by using a stimulus composed of orthogonally moving random-dot patterns. The results indicated that, when the foreground moves with a slower speed, a self-motion sensati on with a component in the same direction as the foreground is induced. We named this novel component of self-motion perception 'inverted vection'. Th e robustness of inverted vection was confirmed using various measures of se lf-motion sensation and under different stimulus conditions. The mechanism underlying inverted vection is discussed with regard to potentially relevan t factors, such as relative motion between the foreground and background, a nd the interaction between the mis-registration of eye-movement information and self-motion perception. (C) 2000 Elsevier Science Ltd. All rights rese rved.