Decisions are expedited through multiple neural adjustments spanning the sensorimotor hierarchy
Dr. Natalie Steinemann, Prof. Redmond O'Connell, Dr. Simon Kelly
Received: 27th September 17
When decision makers prioritize speed over accuracy, neural activity is elevated in brain circuits involved in preparing actions. Such “urgency” signal components, defined by their independence from sensory evidence, are observed even before evidence is presented and can grow dynamically during decision formation. Is urgency applied globally, or are there adjustments of a distinct nature applied at different processing levels? Using a novel multi-level recording paradigm, we show that dynamic urgency impacting cortical action-preparation signals is echoed downstream in electromyographic indices of muscle activation, but does not directly influence upstream cortical levels. A motor-independent representation of cumulative evidence reached lower pre-response levels under conditions of greater motor-level urgency, paralleling a decline in choice accuracy. At the sensory level itself, we find a boost in differential evidence, which is correlated with changes in pupil size and acts to alleviate, rather than contribute to, the overall accuracy cost under speed pressure.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.