@article {LinENEURO.0191-16.2016, author = {Amy Lin and Brian Maniscalco and Biyu J. He}, title = {Scale-Free Neural and Physiological Dynamics in Naturalistic Stimuli Processing}, volume = {3}, number = {5}, elocation-id = {ENEURO.0191-16.2016}, year = {2016}, doi = {10.1523/ENEURO.0191-16.2016}, publisher = {Society for Neuroscience}, abstract = {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: P(f)∝1/fβ, 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){\textemdash}the low-frequency (\<5 Hz) component of brain field potentials{\textemdash}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{\textquoteright} 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.}, URL = {https://www.eneuro.org/content/3/5/ENEURO.0191-16.2016}, eprint = {https://www.eneuro.org/content/3/5/ENEURO.0191-16.2016.full.pdf}, journal = {eNeuro} }