title: Keep focussing: striatal dopamine multiple functions resolved in a single mechanism tested in a simulated humanoid robot.
abstract: The effects of striatal dopamine (DA) on behavior have been widely investigated over the past decades, with "phasic" burst firings considered as the key expression of a reward prediction error responsible for reinforcement learning. Less well studied is "tonic" DA, where putative functions include the idea that it is a regulator of vigor, incentive salience, disposition to exert an effort and a modulator of approach strategies. We present a model combining tonic and phasic DA to show how different outflows triggered by either intrinsically or extrinsically motivating stimuli dynamically affect the basal ganglia by impacting on a selection process this system performs on its cortical input. The model, which has been tested on the simulated humanoid robot iCub interacting with a mechatronic board, shows the putative functions ascribed to DA emerging from the combination of a standard computational mechanism coupled to a differential sensitivity to the presence of DA across the striatum.
authors.affiliation: Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London London, UK.
authors.forename: Vincenzo G
authors.initials: VG
authors.lastname: Fiore
authors.affiliation: Laboratory of Computational Embodied Neuroscience, CNR, Istituto di Scienze e Tecnologie della Cognizione Roma, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Sperati
authors.affiliation: Laboratory of Computational Embodied Neuroscience, CNR, Istituto di Scienze e Tecnologie della Cognizione Roma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mannella
authors.affiliation: Laboratory of Computational Embodied Neuroscience, CNR, Istituto di Scienze e Tecnologie della Cognizione Roma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Mirolli
authors.affiliation: Adaptive Behaviour Research Group, Department of Psychology, University of Sheffield Sheffield, UK.
authors.forename: Kevin
authors.initials: K
authors.lastname: Gurney
authors.affiliation: Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London London, UK.
authors.forename: Karl
authors.initials: K
authors.lastname: Friston
authors.affiliation: Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London London, UK.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Dolan
authors.affiliation: Laboratory of Computational Embodied Neuroscience, CNR, Istituto di Scienze e Tecnologie della Cognizione Roma, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Baldassarre
keywords: basal ganglia; dopamine; iCub; intrinsic motivation; novelty; selection