Exerting too much mentally while working or studying makes people feel drained. New research may explain why this happens, as it shows that more intense and prolonged thoughts can intoxicate the brain.
The study by researchers at the Brain Institute in Paris, published in the scientific journal Current Biology on August 11, explains that, with the increase in toxins in the brain, each person’s control over their own decisions can be altered.
“Our findings show that cognitive work results in a real functional change – accumulation of harmful substances. So, fatigue would, in fact, be a signal that would make us stop working, but with a different purpose: to preserve the integrity of the functioning of the brain. brain,” he explains.
The purpose of the research was to fully understand what mental fatigue is. So they used magnetic resonance spectroscopy (MRS) to monitor brain chemistry over the course of a workday.
Two groups of people were analyzed: those who needed to think a lot and those who had relatively easier cognitive tasks.
People who did heavier work showed signs of fatigue, including reduced pupil dilation. They also demonstrated a shift in choices to options that offered short-term rewards with little effort. In addition, they had higher levels of glutamate in the synapses of the prefrontal cortex of the brain. For the authors, this supports the theory that glutamate accumulation makes the additional activation of the prefrontal cortex greater, so that cognitive control is more difficult after a mentally hard day’s work.
For Pessiglione, there is no measure or action to circumvent this limitation of brain capacity, but he points out that “rest and sleep” can be a good start.
Therefore, researchers are still hoping to do further studies to find out why the prefrontal cortex seems especially susceptible to glutamate accumulation and fatigue, and are particularly curious to know whether the same markers of fatigue in the brain can predict recovery from health conditions, like depression or cancer.