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bioRxiv · 10.1101/2024.06.18.599522

Phasic alertness generates urgency and amplifies competition between evidence accumulators

Tromp, J.·Wurm, F.·Lucchi, F.·De Kleijn, R.·Nieuwenhuis, S.
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Abstract

Although phasic alertness generally benefits cognitive performance, it often increases the interference caused by distracting information, resulting in impaired decision-making and cognitive control. However, it is unclear why phasic alertness has these negative effects. Here, we present a novel, biologically-informed account, according to which phasic alertness generates an evidence-independent urgency signal. This urgency signal shortens overall response times, but also amplifies competition between evidence accumulators, thus slowing down decision-making and impairing cognitive control. The key assumptions of this account are supported with pupil measurements and electrophysiological data from human decision-makers performing an arrow flanker task. We also show that a computational model of the flanker task that incorporates time-varying urgency can reproduce the behavioral effects of phasic alertness, but only when the evidence accumulators compete with each other through lateral inhibition. Our results reveal a close interplay between dynamic changes in urgency, cognitive control and evidence accumulation.

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Tromp, J., Wurm, F., Lucchi, F., De Kleijn, R., Nieuwenhuis, S.. 2024-06-22. Phasic alertness generates urgency and amplifies competition between evidence accumulators. https://doi.org/10.1101/2024.06.18.599522

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