title: Neuronal correlates of decisions to speak and act: Spontaneous emergence and dynamic topographies in a computational model of frontal and temporal areas.
abstract: The neural mechanisms underlying the spontaneous, stimulus-independent emergence of intentions and decisions to act are poorly understood. Using a neurobiologically realistic model of frontal and temporal areas of the brain, we simulated the learning of perception-action circuits for speech and hand-related actions and subsequently observed their spontaneous behaviour. Noise-driven accumulation of reverberant activity in these circuits leads to their spontaneous ignition and partial-to-full activation, which we interpret, respectively, as model correlates of action intention emergence and action decision-and-execution. Importantly, activity emerged first in higher-association prefrontal and temporal cortices, subsequently spreading to secondary and finally primary sensorimotor model-areas, hence reproducing the dynamics of cortical correlates of voluntary action revealed by readiness-potential and verb-generation experiments. This model for the first time explains the cortical origins and topography of endogenous action decisions, and the natural emergence of functional specialisation in the cortex, as mechanistic consequences of neurobiological principles, anatomical structure and sensorimotor experience.
authors.affiliation: Medical Research Council, Cognition and Brain Sciences Unit, 15 Chaucer Rd., Cambridge CB2 7EF, United Kingdom. Electronic address: mg421@cam.ac.uk.
authors.forename: Max
authors.initials: M
authors.lastname: Garagnani
authors.forename: Friedemann
authors.initials: F
authors.lastname: Pulvermüller
mesh_terms: D001931:Brain Mapping; D003198:Computer Simulation; D003657:Decision Making / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007802:Language; D008959:Models, Neurological; D013060:Speech / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*
keywords: Connectivity; Free will; Functional specialisation; Hebbian learning; Language; Neural network; Prefrontal cortex; Readiness potential; Speech; Voluntary action