Scale-Free Neural and Physiological Dynamics in Naturalistic Stimuli Processing.
Neural activity recorded at multiple spatiotemporal scales is dominated by arrhythmic fluctuations without a characteristic temporal periodicity. Such activity often exhibits a 1/f-type power spectrum, in which power falls off with increasing frequency following a power-law function: [Formula: see text], which is indicative of scale-free dynamics. Two extensively studied forms of scale-free neural dynamics in the human brain are slow cortical potentials (SCPs)-the low-frequency (<5 Hz) component of brain field potentials-and the amplitude fluctuations of α oscillations, both of which have been shown to carry important functional roles. In addition, scale-free dynamics characterize normal human physiology such as heartbeat dynamics. However, the exact relationships among these scale-free neural and physiological dynamics remain unclear. We recorded simultaneous magnetoencephalography and electrocardiography in healthy subjects in the resting state and while performing a discrimination task on scale-free dynamical auditory stimuli that followed different scale-free statistics. We observed that long-range temporal correlation (captured by the power-law exponent β) in SCPs positively correlated with that of heartbeat dynamics across time within an individual and negatively correlated with that of α-amplitude fluctuations across individuals. In addition, across individuals, long-range temporal correlation of both SCP and α-oscillation amplitude predicted subjects' discrimination performance in the auditory task, albeit through antagonistic relationships. These findings reveal interrelations among different scale-free neural and physiological dynamics and initial evidence for the involvement of scale-free neural dynamics in the processing of natural stimuli, which often exhibit scale-free dynamics.
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Semel Institute for Neuroscience and Human Behavior, University of California-Los Angeles, Los Angeles, California 90095.
Amy
A
Lin
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
Brian
0000-0003-3116-6188
B
Maniscalco
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA; Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA; Departments of Neurology, Neuroscience and Physiology, and Radiology, New York University Langone Medical Center, New York, NY 10016.
Biyu J
0000-0003-1549-1351
BJ
He
D000161:Acoustic Stimulation; D000328:Adult; D000513:Alpha Rhythm; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009483:Neuropsychological Tests; D012146:Rest; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D055815:Young Adult
arrhythmic brain activity; heart rate variability; natural stimuli; scale-free dynamics; slow cortical potentials; α oscillations