Investigating the speed-accuracy tradeoff: Better use deadlines or response signals?

Michael Dambacher, Ronald Hübner

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Abstract


Deadlines (DL) and response signals (RS) are two well-established techniques to investigate speed-accuracy tradeoffs (SATs). Methodological differences imply, however, that corresponding data do not necessarily reflect equivalent processes. Specifically, the DL procedure grants knowledge about trial-specific time demands and requires responses before a pre-specified period has elapsed. In contrast, RS intervals often vary unpredictably between trials, and responses must be given after an explicit signal. Here, we investigated the effects of these differences in a flanker task. While all conditions yielded robust SAT functions, a right-shift of the curves pointed to reduced performance in RS (Exp. 1: blocked; Exp. 2-3: randomized) compared to DL conditions (Exp. 1-3: blocked), indicating that the detection of the RS imposes additional task demands. Moreover, the flanker effect vanished at long intervals in RS settings, suggesting that stimulus-related effects are absorbed in a slack when decisions complete prior to the signal. In turn, effects of a flat (Exp. 2) vs. a performance- contingent payment (Exp. 3) indicated that susceptibility to response strategies is higher in the DL than in the RS method. Finally, the RS procedure led to a broad range of slow responses and high accuracies, whereas DL conditions resulted in smaller variations in the upper data range (Exp. 1-2); with performance-contingent payment (Exp. 3), though, data ranges became similar. Together, the results uncover characteristic procedure-related effects and should help to select the appropriate technique.

Behavior Research Methods