title: Inhibition of Pre-Supplementary Motor Area by Continuous Theta Burst Stimulation Leads to More Cautious Decision-making and More Efficient Sensory Evidence Integration.
abstract: Decisions are made based on the integration of available evidence. The noise in evidence accumulation leads to a particular speed-accuracy tradeoff in decision-making, which can be modulated and optimized by adaptive decision threshold setting. Given the effect of pre-SMA activity on striatal excitability, we hypothesized that the inhibition of pre-SMA would lead to higher decision thresholds and an increased accuracy bias. We used offline continuous theta burst stimulation to assess the effect of transient inhibition of the right pre-SMA on the decision processes in a free-response two-alternative forced-choice task within the drift diffusion model framework. Participants became more cautious and set higher decision thresholds following right pre-SMA inhibition compared with inhibition of the control site (vertex). Increased decision thresholds were accompanied by an accuracy bias with no effects on post-error choice behavior. Participants also exhibited higher drift rates as a result of pre-SMA inhibition compared with the vertex inhibition. These results, in line with the striatal theory of speed-accuracy tradeoff, provide evidence for the functional role of pre-SMA activity in decision threshold modulation. Our results also suggest that pre-SMA might be a part of the brain network associated with the sensory evidence integration.
authors.affiliation: Koç University, Istanbul, Turkey.
authors.forename: Tuğçe
authors.initials: T
authors.lastname: Tosun
authors.affiliation: University of Pennsylvania.
authors.forename: Dilara
authors.initials: D
authors.lastname: Berkay
authors.affiliation: Maastricht University.
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Sack
authors.affiliation: University of Otago, Dunedin, New Zealand.
authors.forename: Yusuf Ö
authors.initials: YÖ
authors.lastname: Çakmak
authors.affiliation: Koç University, Istanbul, Turkey.
authors.forename: Fuat
authors.initials: F
authors.lastname: Balcı
mesh_terms: D001499:Bayes Theorem; D001931:Brain Mapping; D003657:Decision Making / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008959:Models, Neurological; D009039:Motion Perception / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D013826:Theta Rhythm / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult