Searching and fixating: scale-invariance vs. characteristic timescales   in attentional processes
  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. 
D. P. Shinde, Anita Mehta, R. K. Mishra
cond-mat.stat-mech physics.bio-ph q-bio.NC