Chapter 31 - Oculomotor behavior in natural and man-made environments

Abstract

Distributions of fixation duration and saccade size are low-level behavioral measures that can provide a window into oculomotor performance at a specific level. This chapter describes an experiment in which three subjects performed two tasks in two environments. Fixation duration and saccade size were extracted from eye movements monitored with a wearable eye tracker. Mean, median, and modal fixation durations were shorter during the Free-view task in the Man-made environment than in the Wooded environment. However, despite the difference in characteristics and predictability of the paths between the Man-made and the Wooded environments, there was not a significant environment difference in the distributions of fixation duration during the Walking task. There were no significant differences in the distribution of saccade sizes across any of the conditions. Unlike the fixation-duration and saccade-size distributions, analysis of gaze position during the Walking task provided a more direct measure of the value of visual information gathered during foveations.