United States: Chronic mental fatigue weakens brain areas essential for self-control, leading to increased aggression.
More about the news
A new study published in PNAS connects ego depletion, or the depletion of willpower after prolonged exertion, to changes in brain regions governing executive functions.
Researchers from the IMT School of Advanced Studies Lucca combined neuroscience and economics to explore how fatigue affects the prefrontal cortex, responsible for decision-making.
About Fatigue
Fatigue has been linked to changes in the prefrontal cortex, increasing brain activity typical of sleep, such as EEG delta waves. The concept of ego depletion, first proposed in the early 2000s, suggests that self-regulation is a finite resource—its depletion leads to reduced empathy and increased aggression.
However, more recent studies have questioned this theory, with some failing to reproduce the original results.
In more recent years, however, this theory has been criticized: In subsequent studies, researchers have not always succeeded in reproducing the impact of “consumption” of willpower; if they have succeeded at all, it has been much less than what was observed in the first study. Furthermore, it is unclear what kind of neural effect would underlie such an effect, medicalxpress.com reported.
The new study is an attempt to add a neuroscientific angle to this old problem.
The research on sleep has identified a phenomenon called “local sleep”: it occurs when some areas of the awake person’s brain start showing a typical electrical activity of sleep, for example, delta waves on the EEG.
As pointed out earlier, this is found to occur, especially when one is feeling mentally drained.
According to Erica Ordali, a research fellow at the IMT School and first author of the paper, “Our starting hypothesis was that local sleep would be the neuronal manifestation of the phenomenon of ego depletion known to psychology,” medicalxpress.com reported.