A pre-registered test of competing theories to explain ego depletion effects using psychophysiological indicators of mental effort

Abstract

A prominent, hotly debated idea—the ‘ego depletion’ phenomenon—suggests that engaging in effortful, demanding tasks leads to poorer subsequent self-control performance. Several theories seek to explain the emergence of ego depletion effects. The two most prominent ones are the strength model of self-control (Baumeister & Vohs, 2016) and the process model of self-control (Inzlicht & Schmeichel, 2012). Predictions of these models are predominantly identical on the behavioral level. The models’ predictions differ, however, on the level of invested mental effort. The present pre-registered study (N = 179) contrasted these competing predictions combining an established moderator counteracting ego depletion effects (i.e., self-affirmation) and psychophysiological indicators of mental effort (i.e., systolic blood pressure and pre-ejection period). Our data provide moderate evidence for ego-depletion—decrements in self-control performance after a high- versus low-demanding task in the non-affirmed conditions. Self-affirmation had an unexpected effect: Contrary to previous research, self-affirmed participants performed similarly poorly as participants in the high demand+non-affirmed condition. Although this unexpected finding limited the ability to contrast competing model predictions, it points to hitherto unknown effects of self-affirmation on self-control performance. Systolic blood pressure reactivity emerged as a valid indicator of invested mental effort, but the data show no sign of disengagement after a high demanding task predicted by the process (but not the strength) model. We explore systolic blood pressure progression across the sequential task paradigm, suggest a testable account for the effects of self-affirmation on self-control performance, and discuss theoretical implications of the results for the two competing models.

Ya gotta wanna: Shifting motivational priorities in the self‐control process

“…As noted, the process model has begun to receive more empirical attention in recent years (e.g., Garrison et al, 2017;Gieseler et al, 2020;Sayre et al, 2020), with studies adopting several methodological approaches (e.g., sequential two-task design; Finley & Schmeichel, 2019; functional neuroimaging; see Kelley et al, 2019). However, results have been somewhat mixed.…”

“…First, although findings from several studies have been consistent with process model predictions (e.g., Schmeichel et al, 2010), some results have been mixed or inconsistent with this model (e.g., Garrison et al, 2019;Gieseler et al, 2020;Haynes et al, 2016), raising questions regarding the value of the model in explaining self-control processes. Furthermore, previous empirical work has approached this model in several ways (e.g., the sequential two-task approach common in studies on self-control resource depletion; ; functional neuroimaging and electrophysiological studies; see Kelley et al, 2019; experience sampling techniques; Sayre et al, 2020;Wilkowski et al, 2018).…”