Searching and fixating: scale-invariance vs. characteristic timescales in attentional processes

TL;DR

This study investigates eye movement patterns during semantic search, revealing scale-invariance in saccades and characteristic timescales in fixations, with implications for understanding attentional processes.

Contribution

It demonstrates the coexistence of scale-invariance in saccadic movements and characteristic timescales in fixations, linking eye movement dynamics to Levy and Brownian processes.

Findings

Saccadic distributions are scale-invariant, following Levy dynamics.

Fixation distributions show a characteristic attentional timescale.

Literate subjects exhibit distinct fixation timescales.

Abstract

In an experiment involving semantic search, the visual movements of sample populations subjected to visual and aural input were tracked in a taskless paradigm. The probability distributions of saccades and fixations were obtained and analyzed. Scale-invariance was observed in the saccadic distributions, while the fixation distributions revealed the presence of a characteristic (attentional) time scale for literate subjects. A detailed analysis of our results suggests that saccadic eye motions are an example of Levy, rather than Brownian, dynamics.