TY - JOUR T1 - Dynamic changes in urgency over the course of a decision JF - bioRxiv DO - 10.1101/2020.04.02.022327 SP - 2020.04.02.022327 AU - Gerard Derosiere AU - David Thura AU - Paul Cisek AU - Julie Duque Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/04/07/2020.04.02.022327.abstract N2 - While making decisions, humans and other animals always need to balance the desire to gather sensory information (to make the best choice) with the urge to act, facing a speed-accuracy tradeoff (SAT). Given the ubiquity of the SAT across species, extensive research has been devoted to understanding the computational mechanisms allowing its regulation at different timescales, including from one context to another, and from one decision to another. However, in dynamic environments, animals often need to change their SAT on even shorter timescales – i.e., over the course of an ongoing decision – and very little is known about the mechanisms that allow such rapid adaptations. The present study aimed at addressing this issue. Human subjects performed a modified version of the tokens task, where an increase or a decrease in penalty occurring halfway through the trial promoted rapid SAT shifts, favoring speeded decisions either in the early or in the late stage of the trial. Importantly, these shifts were associated with stage-specific adjustments in the accuracy criterion exploited for committing to a choice and relatedly, with dynamic, non-linear changes in urgency. Those subjects who decreased the most their accuracy criterion at a given decision stage presented the highest gain in speed, but also the highest cost in terms of accuracy at that time. Altogether, the current findings offer a unique extension of former work, by revealing that dynamic changes in urgency allow the regulation of the SAT within the timescale of a single decision. ER -