title: Primary motor cortex contributes to the implementation of implicit value-based rules during motor decisions.
abstract: In the present study, we investigated the functional contribution of the human primary motor cortex (M1) to motor decisions. Continuous theta burst stimulation (cTBS) was used to alter M1 activity while participants performed a decision-making task in which the reward associated with the subjects' responses (right hand finger movements) depended on explicit and implicit value-based rules. Subjects performed the task over two consecutive days and cTBS occurred in the middle of Day 2, once the subjects were just about to implement implicit rules, in addition to the explicit instructions, to choose their responses, as evident in the control group (cTBS over the right somatosensory cortex). Interestingly, cTBS over the left M1 prevented subjects from implementing the implicit value-based rule while its implementation was enhanced in the group receiving cTBS over the right M1. Hence, cTBS had opposite effects depending on whether it was applied on the contralateral or ipsilateral M1. The use of the explicit value-based rule was unaffected by cTBS in the three groups of subject. Overall, the present study provides evidence for a functional contribution of M1 to the implementation of freshly acquired implicit rules, possibly through its involvement in a cortico-subcortical network controlling value-based motor decisions.
authors.affiliation: Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium. Electronic address: gerard.derosiere@uclouvain.be.
authors.forename: Gerard
authors.initials: G
authors.lastname: Derosiere
authors.affiliation: Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Zénon
authors.affiliation: Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Andrea
authors.initials: A
authors.lastname: Alamia
authors.affiliation: Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Duque
mesh_terms: D000328:Adult; D003657:Decision Making / Q000502:physiology*; D004558:Electric Stimulation; D004576:Electromyography; D019054:Evoked Potentials, Motor; D005260:Female; D005385:Fingers; D006801:Humans; D008297:Male; D009043:Motor Activity; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance; D011930:Reaction Time; D012201:Reward; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: Action selection; Action value; Decision-making; Reward; cTBS