TY  - JOUR
PY  - 2016//
TI  - Global gain modulation generates time-dependent urgency during perceptual choice in humans
JO  - Nature communications
A1  - Murphy, Peter R.
A1  - Boonstra, Evert
A1  - Nieuwenhuis, Sander
SP  - e13526
EP  - e13526
VL  - 7
IS  - 
N2  - Decision-makers must often balance the desire to accumulate information with the costs of protracted deliberation. Optimal, reward-maximizing decision-making can require dynamic adjustment of this speed/accuracy trade-off over the course of a single decision. However, it is unclear whether humans are capable of such time-dependent adjustments. Here, we identify several signatures of time-dependency in human perceptual decision-making and highlight their possible neural source. Behavioural and model-based analyses reveal that subjects respond to deadline-induced speed pressure by lowering their criterion on accumulated perceptual evidence as the deadline approaches. In the brain, this effect is reflected in evidence-independent urgency that pushes decision-related motor preparation signals closer to a fixed threshold. Moreover, we show that global modulation of neural gain, as indexed by task-related fluctuations in pupil diameter, is a plausible biophysical mechanism for the generation of this urgency. These findings establish context-sensitive time-dependency as a critical feature of human decision-making.<p />  <p>Language: en</p>
LA  - en
SN  - 2041-1723
UR  - http://dx.doi.org/10.1038/ncomms13526
ID  - ref1
ER  -