Do you sometimes feel irritable or have difficulty deciding after a long day? These sensations are not simple weariness. They could find their origin in a surprising cerebral mechanism: the local exhaustion of certain areas involved in mastery of variety.
Researchers from the IMT School for Advanced Studies Lucca explored this phenomenon through a unique experiment. They asked 44 volunteers to complete prolonged, emotionally demanding cognitive tasks while monitoring their activity brain via an electroencephalogram.
These tests revealed unusual brain activity. Participants forced to have strong control over their emotions showed an increase in delta waves in their prefrontal cortex. These waves, characteristic of sleeptestify to “local drowsiness”. This sleep partial specifically affects brain regions responsible for decision-making and inhibiting impulsive reactions. Clearly, these areas become drowsy without us being aware of it, directly affecting our behavior.
To better understand this impact, the researchers subjected the same participants to cooperation games after the cognitive tasks. Result ? Those who exercised strong emotional control were significantly less cooperative, preferring competitive strategies. The figures are striking: 86% of “rested” participants opted for collaborative behaviors, compared to only 41% of tired participants. These data illustrate the concrete effect of mental fatigue on our social interactions.
In neuroscience, this phenomenon is consistent with the theory of “ego exhaustion”. Formulated in 1998, this theory postulates that human will is a limited resource, exhaustible through prolonged effort. This study provides tangible biological proof. The implications are vast: from negotiation economic to legal agreements, our decisions can be biased by brain exhaustion. A warning against making important decisions during periods of fatigue.
Practical advice emerges: take the time to “sleep” before any important decision. By reactivating our “dormant” brain areas, we could avoid impulsive and regrettable choices.
What is local sleep and how does it affect our brain?
Local sleep is a neurological phenomenon observed in specific areas of the brain while the rest of the brain remains awake. This mechanism, identified by research on sleep, manifests itself by delta brain waves, characteristic of deep sleep, which appear only in certain active brain regions.
During prolonged mental fatigue, these delta waves emerge in the frontal cortex, an area involved in decision-making and self-control. This “localized sleep” leads to a partial deactivation of these regions, impairing the ability to regulate our behaviors and make considered decisions.
The consequences are numerous: decreased cooperation, an increased tendency to aggressiveness and impulsive choices. These results reinforce the importance of regular breaks and rest to preserve the effectiveness of our essential cognitive functions.
