The functional role of cross-frequency coupling

Recent studies suggest that cross-frequency coupling (CFC) might play a functional role in neuronal computation, communication and learning. In particular, the strength of phase-amplitude CFC differs across brain areas in a task-relevant manner, changes quickly in response to sensory, motor and cognitive events, and correlates with performance in learning tasks. Importantly, whereas high-frequency brain activity reflects local domains of cortical processing, low-frequency brain rhythms are dynamically entrained across distributed brain regions by both external sensory input and internal cognitive events. CFC might thus serve as a mechanism to transfer information from large-scale brain networks operating at behavioral timescales to the fast, local cortical processing required for effective computation and synaptic modification, thus integrating functional systems across multiple spatiotemporal scales. Recent studies suggest that cross-frequency coupling (CFC) might play a functional role in neuronal computation, communication and learning. In particular, the strength of phase-amplitude CFC differs across brain areas in a task-relevant manner, changes quickly in response to sensory, motor and cognitive events, and correlates with performance in learning tasks. Importantly, whereas high-frequency brain activity reflects local domains of cortical processing, low-frequency brain rhythms are dynamically entrained across distributed brain regions by both external sensory input and internal cognitive events. CFC might thus serve as a mechanism to transfer information from large-scale brain networks operating at behavioral timescales to the fast, local cortical processing required for effective computation and synaptic modification, thus integrating functional systems across multiple spatiotemporal scales. instantaneous magnitude of a complex-valued signal. Intuitively, a function that interpolates from peak to peak for an oscillatory waveform. oscillations generated by active neuronal tissue often exhibit characteristic rhythms. Traditionally, neuronal oscillations have been divided into different bands, including slow oscillations (<1 Hz) and delta (1–4 Hz), theta (4-8 Hz), alpha (8–12 Hz), beta (12–30) and gamma (>30 Hz) bands, with further subdivisions becoming more common. transient, rhythmic variation in neuronal activity. Often detected as fluctuations in the electric field generated by the summed synaptic activity of a local neuronal population. measure of the position within a full cycle of an oscillatory waveform. Typically measured in radians [–π, π] or degrees [–180, 180]. For example, the peak of a sinusoidal waveform has a phase of 0 radians, whereas the trough has a phase of π radians.