title: Decorrelation of retinal response to natural scenes by fixational eye movements.
abstract: Under natural viewing conditions the input to the retina is a complex spatiotemporal signal that depends on both the scene and the way the observer moves. It is commonly assumed that the retina processes this input signal efficiently by taking into account the statistics of the natural world. It has recently been argued that incessant microscopic eye movements contribute to this process by decorrelating the input to the retina. Here we tested this theory by measuring the responses of the salamander retina to stimuli replicating the natural input signals experienced by the retina in the presence and absence of fixational eye movements. Contrary to the predictions of classic theories of efficient encoding that do not take behavior into account, we show that the response characteristics of retinal ganglion cells are not sufficient in themselves to disrupt the broad correlations of natural scenes. Specifically, retinal ganglion cells exhibited strong and extensive spatial correlations in the absence of fixational eye movements. However, the levels of correlation in the neural responses dropped in the presence of fixational eye movements, resulting in effective decorrelation of the channels streaming information to the brain. These observations confirm the predictions that microscopic eye movements act to reduce correlations in retinal responses and contribute to visual information processing.
authors.affiliation: Departments of Physics.
authors.forename: Irina Yonit
authors.initials: IY
authors.lastname: Segal
authors.affiliation: Departments of Physics.
authors.forename: Chen
authors.initials: C
authors.lastname: Giladi
authors.affiliation: Departments of Physics.
authors.forename: Michael
authors.initials: M
authors.lastname: Gedalin
authors.affiliation: Department of Psychological and Brain Sciences and Graduate Program in Neuroscience, Boston University, Boston, MA 02215.
authors.forename: Michele
authors.initials: M
authors.lastname: Rucci
authors.affiliation: Life Sciences, and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; and.
authors.forename: Mor
authors.initials: M
authors.lastname: Ben-Tov
authors.affiliation: Departments of Physics.
authors.forename: Yam
authors.initials: Y
authors.lastname: Kushinsky
authors.affiliation: Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; and Computer Science and.
authors.forename: Alik
authors.initials: A
authors.lastname: Mokeichev
authors.affiliation: Life Sciences, and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; and ronensgv@bgu.ac.il.
authors.forename: Ronen
authors.initials: R
authors.lastname: Segev
mesh_terms: D000818:Animals; D005133:Eye Movements; D005403:Fixation, Ocular; D012160:Retina / Q000502:physiology*; D014562:Caudata / Q000502:physiology*
keywords: correlation; fixational eye movement; neural coding; retina