Journal of Bioengineering & Biomedical Science

A Neural Control Model for Horizontal Visual, Auditory and Auditory-Visual Bisensory Stimuli Elicited Saccades

Abstract

Xiu Zhai, Chengqian Che, Benjamin D. Mazzarese, Allison V. Colberg and John D. Enderle

To provide a comprehensive investigation of goal-oriented saccades, experiments are designed to trigger fast eye movements by different types of targets, including visual, auditory, and auditory-visual bisensory stimuli. Human saccades are recorded using a high speed eye tracking system. Data is analyzed to produce parameter estimates using system identification technique for a 3rd-order linear horizontal saccadic eye movement model. Saccade characteristics are explored and compared. The auditory-visual stimuli provide the greatest saccade accuracy. Auditory saccades show lower peak velocity and longer duration. Saccade latent period is relatively independent of saccade amplitude, but there is a significant reduction in the bisensory saccades. Neural inputs of saccades are estimated and analyzed as well. Auditory saccades exhibit lower agonist pulse magnitude and longer agonist pulse duration. Antagonist onset delay is longer in auditory saccades. Post saccade phenomena are caused by the post-inhibitory rebound burst of the antagonist motoneurons. There is a higher incidence of dynamic overshoot in auditory saccades than visual saccades, with more in the abducting direction than the adducting direction.