Nonlinear dynamical analysis of eye movement characteristics using attractor plot and first lyapunov exponent

Abstract

The purpose of this study was to clarify eye movement characteristics during a visual search using nonlinear dynamics (chaos analysis). More concretely, the first Lyapunov exponent and the attractor plot were obtained for the time series data of x- and y-directional eye-gaze locations. An attempt was made to compare the first Lyapunov exponent and the attractor plot during a visual search task as a function of layout complexity of the display and to verify whether chaotic properties existed in the fluctuation of eye-gaze locations, and to examine how the scaling properties change as a function of the layout complexity. First Lyapunov exponent of the time series of eye-gaze locations took positive values, and tended to increase with the increase of search task difficulty (layout complexity). The attractor plot drew a trajectory like an ellipse, and the variation in attractor plots tended to be more complicated with the increase of task difficulty.