Simulated power spectral density (PSD) of background electrocorticogram (ECoG)

摘要: The ECoG background activity of cerebral cortex in states rest and slow wave sleep resembles broadband noise. power spectral density (PSD) then may often conform to a power-law distribution: straight line coordinates log vs. frequency. exponent, x, the distribution, 1/fx, ranges between 2 4. These findings are explained with model neural source mutual excitation among pyramidal cells. dendritic response population interactive excitatory neurons an impulse input is rapid exponential rise decay, which can be fitted sum two terms. When that function convolved as kernel pulses from Poisson process summed, resulting “brown” or “black noise conforms time series PSD sleep. slope dependent on rate rise. variation observed attributed level homeostatically regulated by refractory periods neurons. Departures behavior action accompanied local peaks PSD, manifest emergent nonrandom structure ECoG, prevent reliable estimation 1/fx exponents active states. We conclude resting truly low-dimensional noise, state optimal starting point for defining measuring both artifactual physiological structures activated ECoG.