Decoupling speed and accuracy in an urgent decision-making task reveals multiple contributions to their trade-off
- Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, NC, USA
A key goal in the study of decision making is determining how neural networks involved in perception and motor planning interact to generate a given choice, but this is complicated due to the internal trade-off between speed and accuracy, which confounds their individual contributions. Urgent decisions, however, are special: they may range between random and fully informed, depending on the amount of processing time (or stimulus viewing time) available in each trial, but regardless, movement preparation always starts early on. As a consequence, under time pressure it is possible to produce a psychophysical curve that characterizes perceptual performance independently of reaction time, and this, in turn, makes it possible to pinpoint how perceptual information (which requires sensory input) modulates motor planning (which does not) to guide a choice. Here we review experiments in which, on the basis of this approach, the origin of the speed-accuracy trade-off becomes particularly transparent. Psychophysical, neurophysiological, and modeling results in the “compelled-saccade” task indicate that, during urgent decision making, perceptual information—if and whenever it becomes available—accelerates or decelerates competing motor plans that are already ongoing. This interaction affects both the reaction time and the probability of success in any given trial. In two experiments with reward asymmetries, we find that speed and accuracy can be traded in different amounts and for different reasons, depending on how the particular task contingencies affect specific neural mechanisms related to perception and motor planning. Therefore, from the vantage point of urgent decisions, the speed-accuracy trade-off is not a unique phenomenon tied to a single underlying mechanism, but rather a typical outcome of many possible combinations of internal adjustments within sensory-motor neural circuits.
Keywords: choice, computational model, decision making, discrimination, mental chronometry, race to threshold, saccade, subtraction method
Citation: Salinas E, Scerra VE, Hauser CK, Costello MG and Stanford TR (2014) Decoupling speed and accuracy in an urgent decision-making task reveals multiple contributions to their trade-off. Front. Neurosci. 8:85. doi: 10.3389/fnins.2014.00085
Received: 08 January 2014; Accepted: 02 April 2014;
Published online: 23 April 2014.
Edited by:Dominic Standage, Queen's University, Canada
Reviewed by:Michael C. Dorris. Chinese Academy of Sciences, China
David Thura, University of Montreal, Canada
Copyright © 2014 Salinas, Scerra, Hauser, Costello and Stanford. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Emilio Salinas, Department of Neurobiology and Anatomy, Wake Forest School of Medicine, 1 Medical Center Boulevard, Winston-Salem, NC 27157-1010, USA e-mail: email@example.com