a model for the origin and properties of flicker-induced geometric phosphenes模型的起源和性质flicker-induced几何光幻视.pdfVIP

A Model for the Origin and Properties of Flicker-Induced Geometric Phosphenes 1 2 2 Michael Rule , Matthew Stoffregen , Bard Ermentrout * 1 Department of Neuroscience, Brown University, Providence, Rhode Island, United States of America, 2 Department of Mathematics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America, Abstract We present a model for flicker phosphenes, the spontaneous appearance of geometric patterns in the visual field when a subject is exposed to diffuse flickering light. We suggest that the phenomenon results from interaction of cortical lateral inhibition with resonant periodic stimuli. We find that the best temporal frequency for eliciting phosphenes is a multiple of intrinsic (damped) oscillatory rhythms in the cortex. We show how both the quantitative and qualitative aspects of the patterns change with frequency of stimulation and provide an explanation for these differences. We use Floquet theory combined with the theory of pattern formation to derive the parameter regimes where the phosphenes occur. We use symmetric bifurcation theory to show why low frequency flicker should produce hexagonal patterns while high frequency produces pinwheels, targets, and spirals. Citation: Rule M, Stoffregen M, Ermentrout B (2011) A Model for the Origin and Properties of Flicker-Induced Geometric Phosphenes. PLoS Comput Biol 7(9): e1002158. doi:10.1371/journal.pcbi.1002158 Editor: Olaf Sporns, Indiana University, United States of America Received May 11, 2011; Accepted June 28, 2011; Published September 29, 2011 Copyright: 2011 Rule et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the