Dynamic modulation of decision biases by Brainstem Arousal Systems
- University Medical Center Hamburg-Eppendorf, Germany
- University of Amsterdam, Netherlands
- Vrije Universiteit Amsterdam, Netherlands
- Leiden University, Netherlands
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.
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Article and author information
Author details
Sander Nieuwenhuis
Funding
Deutsche Forschungsgemeinschaft (SFB 936/Z1)
- Tobias H Donner
Deutsche Forschungsgemeinschaft (DO1240/3-1)
- Tobias H Donner
Seventh Framework Programme (604102)
- Tobias H Donner
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: All subjects gave written informed consent, and consent to publish. The ethics committee of the Psychology Department of the University of Amsterdam approved the experiments (Id's: 2014-BC-3406; 2015-BC-4613; 2016-BC-6842).
Copyright
© 2017, de Gee et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Dynamic modulation of decision biases by Brainstem Arousal Systems
eLife 6:e23232.
https://doi.org/10.7554/eLife.23232
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