Evidence for a Spatiotemporal Singularity in Percept Formation by Cerebral Cortex
Perception proceeds by cinematic frames that are separated by an endogenous shutter, which is intrinsic to the background spontaneous activity of cerebral cortex. Cinematic displays of spatiotemporal electrocorticograms (ECoG) show turbulence, from which stable spatial patterns emerge that are correlated with perception of conditioned stimuli (CS). Extracting invariant properties of the perceptual patterns requires high-resolution measurements by high-density electrode arrays, highorder FIR filters, and the Hilbert transform giving analytic signals (instantaneous amplitudes and frequencies). Each pattern is preceded by a null spike, which is postulated to reveal a singularity in cortical dynamics that operates the shutter. A piecewise linear model is used to solve the nonlinear differential equations of mesoscopic cortical dynamics. Solutions point to the existence of a limit cycle attractor. The behavioral and physiological circumstances are described by which the trajectory of cortical dynamics may converge to the attractor and precipitate a phase transition, which destroys an existing pattern and initiates a new one.
AM pattern Electrocorticogram (ECoG) Null spike Perceptual frame Phase transition PM pattern (cone) Singularity Vortex
Walter J. Freeman
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
国际会议
The Second International Conference on Cognitive Neurodynamics--2009(第二届国际认知神经动力学会议)
杭州
英文
585-596
2009-11-15（万方平台首次上网日期，不代表论文的发表时间）