Suprathreshold intrinsic dynamics of the human visual system.
Intrinsic high-frequency neural activities have been observed in the visual system of several species, but their functional significance for visual perception remains a fundamental puzzle in cognitive neuroscience. Spatiotemporal integration in the human visual system acts as a low-pass filter and makes the psychophysical observation of high-frequency activities very difficult. A computational model of retino-cortical dynamics (RECOD) is used to derive experimental paradigms that allow psychophysical studies of high-frequency neural activities. A reduced-parameter version of the model is used to quantitatively relate psychophysical data collected in two of these experimental paradigms. Statistical analysis shows that the model's account of the variance in the data is, in general, highly significant. We suggest that psychophysically measured oscillations reflect intrinsic neuronal oscillations observed in the visual cortex.
Purushothaman
Gopathy
G
Department of Electrical and Computer Engineering, University of Houston, Houston, TX 77204-4005, USA. gopathy@uchicago.edu
Oğmen
Haluk
H
Bedell
Harold E
HE
D000200:Action Potentials / Q000502:physiology; D001683:Biological Clocks / Q000502:physiology; D003198:Computer Simulation; D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D015233:Models, Statistical; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D012160:Retina / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*