Non-visually induced smooth pursuit eye movements using sinusoidal target motion.

Non-visually induced smooth pursuit eye movements (SPEM) were assessed in 8 healthy subjects. Targets were the subjects finger tip movements as somatosensory stimulus and a moving sound source as acoustic stimulus. Horizontal sinusoidal target movements were provided at an amplitude of 15 degrees and frequencies of 0.2, 0.4 and 0.8 Hz. In comparison with conventional visually-induced SPEM, low gain and phase lead were observed, particularly at higher frequency target movements. There was considerable inter-individual variability in the non-visual SPEM performance. A positive correlation between the gains of somatosensory and acoustic SPEM was observed in each subject. We suggest a common SPEM generator, including predictive control for the non-visual SPEM and to some extent for the visual SPEM.