title: Dynamic modulation of decision biases by brainstem arousal systems.
abstract: Decision-makers often arrive at different choices when faced with repeated presentations of the same evidence. Variability of behavior is commonly attributed to noise in the brain's decision-making machinery. We hypothesized that phasic responses of brainstem arousal systems are a significant source of this variability. We tracked pupil responses (a proxy of phasic arousal) during sensory-motor decisions in humans, across different sensory modalities and task protocols. Large pupil responses generally predicted a reduction in decision bias. Using fMRI, we showed that the pupil-linked bias reduction was (i) accompanied by a modulation of choice-encoding pattern signals in parietal and prefrontal cortex and (ii) predicted by phasic, pupil-linked responses of a number of neuromodulatory brainstem centers involved in the control of cortical arousal state, including the noradrenergic locus coeruleus. We conclude that phasic arousal suppresses decision bias on a trial-by-trial basis, thus accounting for a significant component of the variability of choice behavior.
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.|Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jan Willem
authors.identifier: 0000-0002-5875-8282
authors.initials: JW
authors.lastname: de Gee
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.|Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.|Amsterdam Brain & Cognition, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Olympia
authors.identifier: 0000-0001-5288-2437
authors.initials: O
authors.lastname: Colizoli
authors.affiliation: Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.|Amsterdam Brain & Cognition, University of Amsterdam, Amsterdam, The Netherlands.|Max Planck UCL Centre for Computational Psychiatry and Ageing Research, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Niels A
authors.identifier: 0000-0002-1134-7996
authors.initials: NA
authors.lastname: Kloosterman
authors.affiliation: Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
authors.forename: Tomas
authors.identifier: 0000-0001-5863-8689
authors.initials: T
authors.lastname: Knapen
authors.affiliation: Institute of Psychology, Leiden University, Leiden, The Netherlands.
authors.forename: Sander
authors.identifier: 0000-0003-2418-3879
authors.initials: S
authors.lastname: Nieuwenhuis
authors.affiliation: Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.|Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands.|Amsterdam Brain & Cognition, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Tobias H
authors.identifier: 0000-0002-7559-6019
authors.initials: TH
authors.lastname: Donner
mesh_terms: D000328:Adult; D001143:Arousal; D001933:Brain Stem / Q000000981:diagnostic imaging / Q000502:physiology*; D003657:Decision Making; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D055815:Young Adult
keywords: Accumulator model; Decision-making; Locus Coeruleus; Neuromodulation; Trial-to-trial variability; fMRI; human; neuroscience