A New Look At Functional Specialization: Neuronal Clocks

Abstract

Functional specialization, a core theory in neuroscience, states that brain structures have emerged to carry out specific sensory, affective, cognitive and motor functions. For instance, the cerebellum, basal ganglia and hippocampus respectively regulate fine motor coordination, voluntary action and motivation, and declarative memory and navigation. This generally-accepted approach provides only a partial explanation when we consider all the other functions that require these brain structures. Neuroscientific research has growingly focused on these other functions of individual brain regions in recent years. Going beyond a classical understanding of functional specialization, brain regions are now studied concerning their computational capabilities that allow them to contribute to several different tasks. According to this view, subregions of the brain constitute temporal organization machines, or neuronal clocks, that contribute to various cognitive and behavioral processes. This review portrays the historical foundations and working principles of this new paradigm increasingly dominating contemporary neuroscience. Brain oscillations that underlie the concept of neuronal clock are studied with regards to the temporal framework they provide for neuronal computations. The cerebellum, basal ganglia and hippocampus, dominated by oscillations at different frequency ranges, are examined as neuronal clocks that provide generic solutions for various functions requiring different temporal resolutions.