Examining Methods for Combining Speed and Accuracy in a Go/No-Go Vigilance Task

In many human performance tasks, researchers assess performance by measuring both accuracy and response time. A number of theoretical and practical approaches have been proposed to obtain a single performance value that combines these measures, with varying degrees of success. In this report, we examine data from a common paradigm used in applied human factors assessment: a go/no-go vigilance task (Smith et al., 2019). We examined whether 12 different measures of performance were sensitive to the vigilance decrement induced by the design, and also examined how the different measures were correlated. Results suggest that most combined measures were slight improvements over accuracy or response time alone, with the most sensitive and representative result coming from the Linear Ballistic Accumulator model. Practical lessons for applying these measures are discussed.

Under pressure: The influence of time limits on human exploration

How does time pressure influence attitudes towards uncertainty? When time is limited, do people engage in different exploration strategies? We study human exploration in a range of four-armed bandit tasks with different reward distributions and manipulate the available time for each decision (limited vs. unlimited). Through multiple behavioral and model-based analyses, we show that reactions towards uncertainty are influenced by time pressure. Specifically, participants seek out uncertain options when time is unlimited, but avoid uncertainty under time pressure. Moreover, larger relative differences in uncertainty between options slowed down reaction times and dampened the drift rate of a linear ballistic accumulator model. These results shed new light on the differential effect of uncertainty and time pressure on human exploration.