Prolonged mental fatigue can wear down brain areas crucial for the individual ability to self-control, and cause people to behave more aggressively. In a new multidisciplinary study published in the PNAS , a group of researchers from neuroscience and economics at the IMT School of Advanced Studies Lucca links the debated concept of "ego depletion", that is to say the diminution of willpower caused by previous exploitation of it, to physical changes in the areas that govern executive functions in the brain. In particular, the fatigue appears to correspond, in the awake brain, to an increase of the EEG waves typical of sleep in the frontal cortex zone dedicated to making decisions.
In the scientific literature, theories regarding so-called ego depletion emerged in the early 2000s. At their core, there is the idea that self-control is a limited cognitive resource for everyone, and therefore, the more it is exercised, the more it is exhausted. The literature in behavioral economics has used various types of cognitive manipulations typical of economic games to show the effect of ego depletion on behavior, for example less empathy towards others, a lower tendency to act altruistically, or a greater propensity to aggression.
In more recent years, however, this theory has been criticized: subsequent studies have not always managed to replicate the effect of "consumption" of willpower for individuals engaged in strenuous cognitive tasks or, if they have succeeded, they have found a mu.
