Lay summary

The ability to exert control over dominant response tendencies such as impulses, emotions, and thoughts is crucial for living in line with personal standards and social norms. For example, it is important to (more often than not) withstand the impulse to eat tempting, but possibly unhealthy food in order to keep a healthy diet and avoid unnecessary health problems. In psychology, this ability is called self-control.

Self-control is an influential topic of research in psychology and various theoretical models try to understand the processes underlying self-control and (the conditions for) its failures. One influential model by Baumeister and colleagues (Muraven & Baumeister, 2000) postulates that self-control relies on a limited and domain-independent resource. The model assumes that any behavior requiring self-control reduces this resource, leading to a state of ‘self-control depletion’ and augmenting the likelihood of self-control failures in any further attempt at recruiting the resource. For example, according to this model, someone who had to exert control for not choosing an unhealthy desert at lunch would be more likely to react aggressively after a provocation thereafter. Both activities have little in common except that they require self-control (withstanding the temptation to eat an unhealthy desert and withstanding the urge to react aggressively after being provoked). Because the model assumes that self-control relies on a domain-independent resource, exerting control in one domain can hamper subsequent control in a quite different domain.

On the neuronal level there have been several studies investigating the neural mechanisms of successful self-control. However, there has been very little research investigating the consequences of exerted self-control for later attempts at self-control, which is at the core of the model we aim to investigate in the current project. Therefore, the neural underpinnings of self-control failure as a consequence of reduced self-control resources are largely unknown.

The major aim of the project is to examine whether and how the concepts of self-control depletion and its mitigation can be applied to the neural level using functional magnetic resonance imaging (fMRI) and electroencephalographical recordings (EEG). In the first part of the project we will investigate the model’s central assumption of the domain-independent resource enabling successful self-control on the neural level. Therefore we examine whether changes in brain activity after self-control exertion are truly similar across several tasks that all require self-control. In addition, we will investigate how self-control depletion affects the dynamic interplay of impulses and control. In theory, self-control depletion could strengthen impulse strength, leading to impulses that are more difficult to control than under normal circumstances. Other evidence from behavioral psychological research suggests that self-control depletion weakens the ability to control. In addition, both processes could take place at the same time: enhanced impulses and reduced ability to control. Therefore, we will investigate the influence of self-control depletion on brain areas associated with impulsive processes on one side, and on brain areas involved in exerting control and down regulating the activity of the areas involved in impulsive processing on the other side.

We seek to establish a neural pattern that is associated with self-control depletion in the first part of the project, possibly depending on characteristics of the particular tasks that will have been employed. In the second part of the project, we aim at investigating whether different interventions known to counteract self-control depletion effects on the behavioral level (e.g., motivation to perform well, praying) are capable to abolish these effects on the neural level as well. That is, what are the underlying neural processes associated with improved self-control performance brought about by, for example, an increased motivation to perform well?

The proposed studies offer a unique combination of social psychological theory and neuroscientific methodology to address concepts of the resource model of self-control that cannot be answered based on any subdiscipline alone. Our findings will substantially deepen our understanding of the strength model of self control and its metaphorical resource and will prepare the ground for more advanced interventions to improve self-control using both behavioral and neuropsychological methodology.