SpecialityUniversità di Trento, IT

Functional relevance and limits of scale-free temporal brain fluctuationsA growing body of evidence indicates that fluctuations in ongoing brain signals have a ‘fractal’ organization as reflected in the power-law scaling of the power spectrum and in the long-range memory of the autocorrelation function. However, this scale-free behavior is typically restricted to two orders of magnitude and significantly varies across different levels of the brain organization. Here, I describe a series of key studies showing fractal dynamics of broadband fluctuations in electrophysiological signals, from single-cell recordings to macroscopic measures (EEG/MEG) of the brain activity. The findings suggest that, although variable and limited in time scale extension, fractal dynamics is robustly observed at different levels of brain organization, and dynamically regulated by physiological parameters like age, sleep and anesthesia as well as by sensorimotor and cognitive functions.