Decreasing arousal modulates perceptual decision-making

• Published in: bioRxiv
• Main Authors: Jagannathan, Sridhar R, Bareham, Corinne A, Bekinschtein, Tristan A
• Format: Paper
• Language: English
• Published: Cold Spring Harbor Cold Spring Harbor Laboratory Press 23.01.2021
• Subjects: Arousal; Cognition; Cognitive ability; Computational neuroscience; Decision making; Drift; Psychophysics
• DOI: 10.1101/2020.07.23.218727

ABSTRACT The ability to make decisions based on external information, prior knowledge, evidence and context, is a crucial aspect of cognition and may determine the success and survival of an organism. Despite extensive work on decision making mechanisms and models, understanding the effects of arousal on its neural and cognitive processes remain limited. Here we characterise behavioural and neural dynamics of perceptual decision making in awake and low alertness periods in humans, and characterise the compensatory mechanisms as arousal decreases. Well-rested human participants, fluctuating between full wakefulness and low alertness, performed an auditory tone-localisation task and its behavioural dynamics was quantified with psychophysics, signal detection theory and drift-diffusion modelling, revealing slower reaction times, inattention to the left side of space, and a lower rate of evidence accumulation in periods of low alertness. Unconstrained multivariate pattern analysis (decoding) showed a ~260ms delayed onset driven by low alertness of the neural signatures differentiating between left and right decision, with a spatial reconfiguration from centro-parietal to lateral frontal regions 160-300ms. To understand the neural compensatory mechanisms with decreasing arousal, we connected the evidence-accumulation behavioural parameter to the neural activity, showing in the early period (150-300ms) a shift in the associated patterns from bilateral inferior frontal gyri in awake to right dorsolateral in low alertness. The second period of evidence accumulation shows posterior involvement in awake and, due to the delayed processing during drowsiness, a wide frontopolar, dorsolateral prefrontal cortices and right parietal during decreased arousal. The change in the neurobehavioural dynamics for both perceptual encoding and central accumulation cognitive processes define a clear reconfiguration of the brain networks’ regions and dynamics needed for the implementation of decision making in both early perceptual and later central processes, revealing compensatory mechanisms of resilience of cognition when challenged by decreased arousal. Competing Interest Statement The authors have declared no competing interest. Footnotes * We have added new analysis (response based decoding) and rewrote the paper to submit to another journal for review.