Toward a unified view of the speed-accuracy trade-off

摘要

Hasty decisions often lead to poor choices, whereas accurate decisions are ineffective if they take too long. Thus, good choices require cognitive mechanisms to determine the appropriate balance between speed and accuracy, and to control decision processing accordingly. This balance is referred to as the speed-accuracy trade-off (SAT) and the mechanisms by which it is determined and imposed are the subject of this Frontiers Research Topic. Given the near-ubiquity of the SAT across species and experimental tasks, it is not surprising that a wide range of methods have been used to investigate it. Our aim is to provide a unified view of the SAT in light of this diverse methodology. Computationally, decision making and the SAT are well characterized by the framework of bounded integration , providing a solid foundation for this view. Under this framework, noisy evidence for the available choices is added up (integrated) until the running total for one of them reaches a criterion (the bound). The SAT is readily controlled by the bound, where a higher bound favors accuracy at the expense of speed and vice versa . In this collection, we use bounded integration as a reference point for considering the factors that determine the optimal balance between speed and accuracy, the interpretation of behavior by different models from this general class, and the neural implementation of the computations captured by these models. Articles herein further consider conditions under which the above descriptions of the SAT and bounded integration do not explain behavior, and the utility of the SAT for manipulating the context of decisions.The review by Heitz ( 2014 ) describes the history of the SAT as a quantifiable behavioral phenomenon and provides a critical appraisal of methodologies for its study. His historical account describes the shaping of decision theory by the SAT, a perspective that nicely sets up the original research article by Ivanoff et al. ( 2014 ), who used SAT methodology to investigate spatial compatibility effects, that is, how the respective locations of stimuli and responses can influence behavior. They found that SAT manipulations can systematically promote or impede the efficacy of stimulus-response mappings.Stone ( 2014 ) investigated the relationship between speed and accuracy in his original research article, reasoning that the information gained by the observation of evidence should be reflected in both the speed and accuracy of decisions. By fitting a bounded integration model to experimental data, he used model parameters to estimate the mutual information between perceptual evidence and speed, and between perceptual evidence and accuracy. These measures provide bounds on the information gained by the observation of evidence and were used to calculate the smallest detectable change in the strength of evidence.Salinas et al. ( 2014 ) reviewed recent studies of perceptual decisions under extreme time pressure. In this context, the respective contributions of perception and motor planning to choice behavior can be distinguished from one another, quantifying how the former guides the latter. These experiments showed that perceptual information can accelerate or decelerate the competition between ongoing motor plans, revealing the SAT as the combined effect of multiple adjustments to decision processing, not a monolithic phenomenon.The isolation of perception from motor planning under extreme time pressure (Salinas et al., 2014 ) is manifest in the independence of accuracy from decision time, which constitutes a violation of the SAT. Another well-known violation is the improvement in speed and accuracy while learning a task. This improvement is readily captured by increasing a parameter that loosely corresponds to the difference in strength between sources of evidence, often referred to as “drift.” In effect, learning mimics a decrease in task difficulty. In their original research article, Zhang and Rowe ( 2014 ) used a bounded integration model to investigate the effects of speed and accuracy emphasis during and after learning. Under accuracy emphasis, increasing the bound and the drift captured subjects' behavior at the beginning of learning, whereas only an increase in the bound captured behavior after learning. Their results suggest that learning and speed-accuracy emphasis differentially influence decision processing on different timescales.It is widely accepted that the objective of the SAT is to optimize decisions in terms of reward rate, that is, decision makers aim to maximize the pay-off of the task at hand. Three original research articles in the collection investigated optimal decision making, each considering a different set of conditions and corresponding strategies. Khodadadi et al. ( 2014 ) considered the case of a limited time interval, during which decision makers can make as many (or as few) decisions as they wish. This task can be formulated as a search for the reward-maximizing b