stochastic resonance modulates neural synchronization within and between cortical sources随机共振调节神经内同步和皮质之间的来源.pdf

Stochastic Resonance Modulates Neural Synchronization within and between Cortical Sources 1,2 1 1 Lawrence M. Ward *, Shannon E. MacLean , Aaron Kirschner 1 Department of Psychology, University of British Columbia, Vancouver, Canada, 2 The Brain Research Centre, University of British Columbia, Vancouver, Canada Abstract Neural synchronization is a mechanism whereby functionally specific brain regions establish transient networks for perception, cognition, and action. Direct addition of weak noise (fast random fluctuations) to various neural systems enhances synchronization through the mechanism of stochastic resonance (SR). Moreover, SR also occurs in human perception, cognition, and action. Perception, cognition, and action are closely correlated with, and may depend upon, synchronized oscillations within specialized brain networks. We tested the hypothesis that SR-mediated neural synchronization occurs within and between functionally relevant brain areas and thus could be responsible for behavioral SR. We measured the 40-Hz transient response of the human auditory cortex to brief pure tones. This response arises when the ongoing, random-phase, 40-Hz activity of a group of tuned neurons in the auditory cortex becomes synchronized in response to the onset of an above-threshold sound at its ‘‘preferred’’ frequency. We presented a stream of near-threshold standard sounds in various levels of added broadband noise and measured subjects’ 40-Hz response to the standards in a deviant-detection paradigm using high-density EEG. We used independent component analysis and dipole fitting to locate neural sources of the 40-Hz response in b