Pupil diameter encodes the idiosyncratic, cognitive complexity of belief updating
Abstract
Pupils tend to dilate in response to surprising events, but it is not known whether these responses are primarily stimulus driven or instead reflect a more nuanced relationship between pupil-linked arousal systems and cognitive expectations. Using an auditory adaptive decision-making task, we show that evoked pupil diameter is more parsimoniously described as signaling violations of learned, top-down expectations than changes in low-level stimulus properties. We further show that both baseline and evoked pupil diameter is modulated by the degree to which individual subjects use these violations to update their subsequent expectations, as reflected in the complexity of their updating strategy. Together these results demonstrate a central role for idiosyncratic cognitive processing in how arousal systems respond to new inputs and, via our complexity-based analyses, offer a potential framework for understanding these effects in terms of both inference processes aimed to reduce belief uncertainty and more traditional notions of mental effort.
Data availability
All data that support the findings in this article are available at https://osf.io/4ahkx/wiki/home/. All code used in the preparation of this article can be found at https://osf.io/4ahkx/wiki/home/ and https://github.com/TheGoldLab/Analysis_Filipowicz_Glaze_etal_Audio_2AFC .
Article and author information
Author details
Funding
NSF (NSF-NCS 1533623)
- Joseph W Kable
- Joshua I Gold
NIBIB (R01 EB026945)
- Joshua I Gold
NIMH (F32 MH117924)
- Alexandre L S Filipowicz
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: The study protocol was reviewed and approved by the University of Pennsylvania's Institutional Review Board. All subjects provided written informed consent prior to participating in the study. (IRB Protocol # 816727).
Copyright
© 2020, Filipowicz 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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