Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Movement Disorder and Neuromodulation Unit, Department of Neurology, Charité Campus Mitte, Berlin, Germany; Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Core Facility Genomics, Berlin, Germany
Owen Gray
Division of Imaging Science and Technology, Medical School, University of Dundee, Dundee, United Kingdom
Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Movement Disorder and Neuromodulation Unit, Department of Neurology, Charité Campus Mitte, Berlin, Germany
William Gilmour
Division of Imaging Science and Technology, Medical School, University of Dundee, Dundee, United Kingdom
J Douglas Steele
Division of Imaging Science and Technology, Medical School, University of Dundee, Dundee, United Kingdom
Andrea A Kühn
Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Movement Disorder and Neuromodulation Unit, Department of Neurology, Charité Campus Mitte, Berlin, Germany; Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Core Facility Genomics, Berlin, Germany; Berlin School of Mind and Brain, Charité - University Medicine Berlin, Berlin, Germany; NeuroCure, Charité - University Medicine Berlin, Berlin, Germany; DZNE, German Centre for Degenerative Diseases, Berlin, Germany
Division of Imaging Science and Technology, Medical School, University of Dundee, Dundee, United Kingdom; Department of Neurology, Ninewells Hospital & Medical School, Dundee, United Kingdom
Every decision that we make involves a conflict between exploiting our current knowledge of an action’s value or exploring alternative courses of action that might lead to a better, or worse outcome. The sub-cortical nuclei that make up the basal ganglia have been proposed as a neural circuit that may contribute to resolving this explore-exploit ‘dilemma’. To test this hypothesis, we examined the effects of neuromodulating the basal ganglia’s output nucleus, the globus pallidus interna, in patients who had undergone deep brain stimulation (DBS) for isolated dystonia. Neuromodulation enhanced the number of exploratory choices to the lower value option in a two-armed bandit probabilistic reversal-learning task. Enhanced exploration was explained by a reduction in the rate of evidence accumulation (drift rate) in a reinforcement learning drift diffusion model. We estimated the functional connectivity profile between the stimulating DBS electrode and the rest of the brain using a normative functional connectome derived from heathy controls. Variation in the extent of neuromodulation induced exploration between patients was associated with functional connectivity from the stimulation electrode site to a distributed brain functional network. We conclude that the basal ganglia’s output nucleus, the globus pallidus interna, can adaptively modify decision choice when faced with the dilemma to explore or exploit.
