Physical labor is exhausted. In fact, long -term brain labor will have similar effects. Sitting hard for a few hours will make people feel tired.

Now, scientists have new evidence to explain this. A study published on August 11 in "Current Biology" showed that the reason for nervous thinking and feeling exhaustion (not sleepy) was not all in my mind.

This new study shows that when the intense cognitive work lasted for several hours,Packing toxic acid in the forehead cortex in the brain. The accumulation of glutamic acid makes the cost of the prefrontal cortex further, so when cognitive fatigue appears, people will turn to low -cost actions that do not need to work hard or wait.

Mathias PESSIGLIONE in the University of Paris, France said: & ldquo; long -term thinking will lead to the accumulation of toxic substances, and it will be a signal that stops our work, the purpose is to protect the integrity of the brain function. & rdquo;

Scientists point out,We cannot directly eliminate glutamic acid to keep the brain trying hard to think and no longer tired, and can only take rest and sleep.

PESSIGLIONE also suggested that people should avoid making important decisions during fatigue.