Date Published: January 22, 2019
Publisher: Public Library of Science
Author(s): Chris Englert, Dennis Koroma, Alex Bertrams, Corinna S. Martarelli, Magdalena Ewa Król.
The attention control video has been frequently applied to test the ego depletion effect. However, its validity has never been tested, a shortcoming we address in this preregistered study. In the first task, self-control strength was temporarily depleted in the depletion condition (n = 56) but remained intact in the control condition (n = 56). The attention control video served as the secondary task, and we assumed that the depletion condition would perform significantly worse compared to the control condition. Attention regulation was measured with an eye-tracking device. The results revealed that the gaze behavior in the two conditions differed statistically significantly; however, the actual difference was small, indicating that the attention control video may not be an optimal measure of self-control.
Volitionally controlling one’s attention, impulses, emotions, or thoughts can be difficult and cannot always be accomplished, as self-control does not always work . The strength model posits that all different facets of self-control are based on one metaphorical global self-control energy resource with limited capacity . Individuals’ self-control strength can become temporarily depleted after they work on a self-control task. In a state of ego depletion, subsequent self-control performance suffers .
We conducted analyses of variance and report p-values, confidence intervals, and partial eta squared as measure of effect size (for full data set, see https://figshare.com/articles/Data_set/7203029). To quantify how much the data should shift our belief in favor of the null or the alternative hypothesis, we computed Bayes Factors (BF10 where 1 means that the two hypotheses are equally likely, larger values indicate more evidence for the alternative hypothesis, and smaller values indicate more evidence for the null hypothesis). All Bayesian analyses were computed with JASP version 0.8.6.
Recent studies questioned the validity of the strength model [7–12] which led to a scientific debate regarding the magnitude of the ego depletion effect [13,31] and motivated us to analyze the validity of the attention control video . The attention control video has often been used in ego depletion research [17–20]. It is postulated that self-control strength needs to be invested in order to ignore certain stimuli . Therefore, we applied the sequential two-task paradigm : In the first step, participants were either depleted or not depleted, while the attention control video was used as the dependent variable. We expected that depleted participants would be less adept at looking at a target stimulus in the presence of distracting stimuli than participants in the control condition.
The present study found only moderate empirical evidence for the assumption that the attention control video requires self-control strength. It seems promising to adopt objective measures of self-control (e.g. eye tracking) in order to dig deeper into the true nature of the ego depletion effect. Future studies should also focus on investigating whether there is actually something like a limited self-control resource. Previous research suggested that glucose seems to be the driving physiological force of self-control performance , however these findings have been difficult to replicate [38,39]. To conclude, currently there seem to be more questions than answers in regard to the ego depletion effect and more rigorous research adopting appropriate research designs is highly necessary.