Interaction of optokinetic and vestibular stimuli in motion perception.

The ssnsation of self-rotation (circularvection) was produced by rotation of a stripe pattern to the left or to the right at constant angular velocity. During circularvection, subjects were randomly accelerated in constant acceleiation steps. Ths major experimental findings are:1. Thresholds for detection of angular acceleration are raised when this acceleration is opposite to the direction of circularvection. Times to detect these accelerations are similarly increased.2. Magnitude estimates of angular velocity show the effect of a visually induced velocity offset which is increased slightly by vestibular responses in the same direction and decreased markedly when the vestibular responses are in the direction opposite to self-rotation.3. Many of the effects of angular acczleration on psrceived velocity are accurately predicted by the adaptation model of the vestibular system. However, an important nonlinear interaction exists whereby Iapidly occurring conflicts between visual and vestibular sensation, esp...