Model analysis of influence of mental workload on vestibulo-ocular reflex

Abstract

The vestibulo-ocular reflex (VOR), which is a reflexive eye movement generated in the direction opposite to that of the head movement, is affected by mental workload(MWL). A computational model to estimate the VOR from head movement has been proposed. Previous research has shown that when humans perform mental tasks, the error between the measured and the estimated VOR (calculated with the mathematical model) increased. Previously, a computational model for estimating the VOR was proposed; this model, known as the 6DOF-SVC model considered several processes of self-motion estimation. Further, another study revealed that a parameter in this computational model representing self-motion estimation changed as a result of volition of the head movement. This result indicated that the activeness or passiveness of the head movement influenced the outcome. However, the relationship between added mental tasks and the model self-motion estimation parameter has not yet been investigated. Therefore, in this study, an experiment to investigate the effect of mental tasks on the modeling error and the model parameter was implemented. Specifically, movements of the eye and head were measured when participants were exposed to a pitching vibration with and without a mental task to perform. The experimental results showed that the modeling error increased and the model self-motion estimation parameter decreased with the addition of a mental task. Moreover, a positive correlation was found between the model parameter and the VOR gain, which was calculated from the peak eye and head angular velocities.