stroop {afex}R Documentation

Stroop data from Lin et al. (2020, Psych. Science)


Lin, Saunders, Friese, Evans, and Inzlicht (2020) investigated ego depletion. An initial high-demand task was followed by a Stroop task. The data of the Stroop task from all 4 of their studies is included here.




A data frame with 246600 rows and 7 variables:


participant id (preceded by study id), factor with 685 levels


experimental condition (control/low demand, deplete/high demand), factor with 2 levels


study number (1, 2, 3, 4), factor with 4 levels


trial number


Stroop congruency (congruent, incongruent), factor with 2 levels


accuracy (0: error, 1: correct)


reaction time (seconds)


Their abstract: People feel tired or depleted after exerting mental effort. But even preregistered studies often fail to find effects of exerting effort on behavioral performance in the laboratory or elucidate the underlying psychology. We tested a new paradigm in four preregistered within-subjects studies (N = 686). An initial high-demand task reliably elicited very strong effort phenomenology compared with a low-demand task. Afterward, participants completed a Stroop task. We used drift-diffusion modeling to obtain the boundary (response caution) and drift-rate (information-processing speed) parameters. Bayesian analyses indicated that the high-demand manipulation reduced boundary but not drift rate. Increased effort sensations further predicted reduced boundary. However, our demand manipulation did not affect subsequent inhibition, as assessed with traditional Stroop behavioral measures and additional diffusion-model analyses for conflict tasks. Thus, effort exertion reduced response caution rather than inhibitory control, suggesting that after exerting effort, people disengage and become uninterested in exerting further effort.


Lin, H., Saunders, B., Friese, M., Evans, N. J., & Inzlicht, M. (2020). Strong Effort Manipulations Reduce Response Caution: A Preregistered Reinvention of the Ego-Depletion Paradigm. *Psychological Science*, doi:10.1177/0956797620904990

[Package afex version 1.3-1 Index]