title: Scaling of horizontal and vertical fixational eye movements.
abstract: Eye movements during fixation of a stationary target prevent the adaptation of the visual system to continuous illumination and inhibit fading of the image. These random, involuntary, small movements are restricted at long time scales so as to keep the target at the center of the field of view. Here we use detrended fluctuation analysis in order to study the properties of fixational eye movements at different time scales. Results show different scaling behavior between horizontal and vertical movements. When the small ballistic movements, i.e., microsaccades, are removed, the scaling exponents in both planes become similar. Our findings suggest that microsaccades enhance the persistence at short time scales mostly in the horizontal component and much less in the vertical component. This difference may be due to the need for continuously moving the eyes in the horizontal plane, in order to match the stereoscopic image for different viewing distances.
authors.affiliation: Minerva Center and Department of Physics, Bar-Ilan University, Ramat-Gan, Israel. jrliang@math.ecnu.edu.cn
authors.forename: Jin-Rong
authors.initials: JR
authors.lastname: Liang
authors.forename: Shay
authors.initials: S
authors.lastname: Moshel
authors.forename: Ari Z
authors.initials: AZ
authors.lastname: Zivotofsky
authors.forename: Avi
authors.initials: A
authors.lastname: Caspi
authors.forename: Ralf
authors.initials: R
authors.lastname: Engbert
authors.forename: Reinhold
authors.initials: R
authors.lastname: Kliegl
authors.forename: Shlomo
authors.initials: S
authors.lastname: Havlin
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005133:Eye Movements / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D009949:Orientation / Q000502:physiology; D012438:Saccades / Q000502:physiology