title: Tuning the Brake While Raising the Stake: Network Dynamics during Sequential Decision-Making.
abstract: When gathering valued goods, risk and reward are often coupled and escalate over time, for instance, during foraging, trading, or gambling. This escalating frame requires agents to continuously balance expectations of reward against those of risk. To address how the human brain dynamically computes these tradeoffs, we performed whole-brain fMRI while healthy young individuals engaged in a sequential gambling task. Participants were repeatedly confronted with the option to continue with throwing a die to accumulate monetary reward under escalating risk, or the alternative option to stop to bank the current balance. Within each gambling round, the accumulation of gains gradually increased reaction times for "continue" choices, indicating growing uncertainty in the decision to continue. Neural activity evoked by "continue" choices was associated with growing activity and connectivity of a cortico-subcortical "braking" network that positively scaled with the accumulated gains, including pre-supplementary motor area (pre-SMA), inferior frontal gyrus, caudate, and subthalamic nucleus (STN). The influence of the STN on continue-evoked activity in the pre-SMA was predicted by interindividual differences in risk-aversion attitudes expressed during the gambling task. Furthermore, activity in dorsal anterior cingulate cortex (ACC) reflected individual choice tendencies by showing increased activation when subjects made nondefault "continue" choices despite an increasing tendency to stop, but ACC activity did not change in proportion with subjective choice uncertainty. Together, the results implicate a key role of dorsal ACC, pre-SMA, inferior frontal gyrus, and STN in computing the trade-off between escalating reward and risk in sequential decision-making.
  
  
  
  Using a paradigm where subjects experienced increasing potential rewards coupled with increasing risk, this study addressed two unresolved questions in the field of decision-making: First, we investigated an "inhibitory" network of regions that has so far been investigated with externally cued action inhibition. In this study, we show that the dynamics in this network under increasingly risky decisions are predictive of subjects' risk attitudes. Second, we contribute to a currently ongoing debate about the anterior cingulate cortex's role in sequential foraging decisions by showing that its activity is related to making nondefault choices rather than to choice uncertainty.
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: David
authors.identifier: 0000-0001-9689-0869
authors.initials: D
authors.lastname: Meder
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: Brian Numelin
authors.initials: BN
authors.lastname: Haagensen
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: Oliver
authors.initials: O
authors.lastname: Hulme
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: Tobias
authors.identifier: 0000-0003-1079-9891
authors.initials: T
authors.lastname: Morville
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: Sofie
authors.initials: S
authors.lastname: Gelskov
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: Damian Marc
authors.initials: DM
authors.lastname: Herz
authors.affiliation: Clinic of Psychiatry, Faculty of Medicine, Vilnius University, Vilnius, 10309, Lithuania, Child and Adolescent Psychiatry Clinic 1, Department of Psychiatry, Region Zealand, Roskilde, 4000, Denmark.
authors.forename: Beata
authors.initials: B
authors.lastname: Diomsina
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark, Department of Neuroscience and Pharmacology and Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, 2000, Denmark, Cognitive Neuroscience Research Unit, Aarhus University, Aarhus, 8000, Denmark, and.
authors.forename: Mark Schram
authors.initials: MS
authors.lastname: Christensen
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark.
authors.forename: Kristoffer Hougaard
authors.initials: KH
authors.lastname: Madsen
authors.affiliation: Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, 2650, Denmark, Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, 2400, Denmark hartwig.siebner@drcmr.dk.
authors.forename: Hartwig Roman
authors.initials: HR
authors.lastname: Siebner
mesh_terms: D063132:Connectome; D003657:Decision Making; D005071:Evoked Potentials; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology*; D006801:Humans; D008297:Male; D012201:Reward; D012309:Risk-Taking
keywords: ACC; action selection; conflict; inhibition; pre-SMA