Modal behavior of cortical neural networks during visual processing.
The network behavior of cortical cells during the processing of a light flash was characterized in an isolated, but functionally intact, turtle visual system. Rapid changes in intracellular membrane potential were monitored optically using a voltage-sensitive dye (VSD). Spatially coherent changes in membrane potential were determined by subjecting high-speed movies of the VSD signals to Karhunen-Loéve decomposition. In all experimental trials analyzed (n > 50), coherent activity was restricted to a small number of similar spatial patterns or modes. At least four modes (M(1,1), M(1,2), M(2,1), and M(2,2)) have an organizational structure similar to the normal modes of a vibrating membrane (drum). This empirical observation of modal activity provides a useful framework for analyzing the macroscopic behavior of cortical networks.
Senseman
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DM
Cajal Neuroscience Research Center, Divisions of Life Sciences and Computer Science, The University of Texas at San Antonio, San Antonio, Texas 78249, USA.
Robbins
K A
KA
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D008433:Mathematics; D008564:Membrane Potentials / Q000502:physiology; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D010775:Photic Stimulation; D014426:Turtles; D014796:Visual Perception / Q000502:physiology*