A Replication of the Ego-Depletion Effect: Control of Effort Engagement
during the Depleting Task with Electroencephalography and Heart-Rate
Variability
Abstract
The ego-depletion effect has been interpreted as a temporary failure of
self-control exertion after a first effortful task (Baumeister et al.,
2007). Although the existence of this effect was previously challenged
(Vohs et al., 2021), it was successfully replicated in a recent study
applying an adequate experimental protocol (Mangin et al., 2021). In the
present experiment, we applied a similar protocol while assessing the
electrophysiological changes in effort engagement through mid-frontal
theta and cardiac reactivity (Cavanagh & Frank, 2014; Mukherjee et al.,
2011). A total of 32 participants in a between-subjects design performed
the following task sequence: handgrip task at 13% of maximal voluntary
contraction, a 30-min mental task (depleting or control task) and the
handgrip task again (dependent task). The experimental group (N = 16)
performed a modified Stroop task, while the control group (N = 16)
watched an emotionally neutral documentary. EEG and ECG were recorded on
a continuous basis. We assumed to observe an increase in the
electrophysiological correlates of mental effort during the depleting
task and a performance decrement in the subsequent dependent task. For
the depleting condition, the behavioral results showed worse performance
in the subsequent dependent task and the EEG results showed higher
mid-frontal theta power. Heart-rate variability results showed an
increase in parasympathetic activity over time during the depleting
task. Therefore, the ego-depletion effect was once again successfully
replicated. The depleting task required more mental effort than the
control task, but a slight decrease in effort engagement over time was
also observed.