“Influential theories suggest that fatigue is an illusion created by the brain that causes us to stop whatever we’re doing and engage in more satisfying activities,” said study author Matthia, research director at Inserm at the Paris Institute for Brain and Spine Research Mathias Pessiglione said. , in a press release. “Our findings suggest that cognitive work leads to real functional changes — the accumulation of harmful substances — so fatigue is indeed a signal to stop working, but for a different purpose: to preserve the integrity of brain function.”
For the study, 40 people were given an easy or difficult version of a task that involved distinguishing letters on a screen for more than six hours. According to the study, participants reported their level of fatigue, and the researchers used magnetic resonance spectroscopy (MRS) to monitor their metabolic responses throughout the study.
Each participant can then choose an immediately satisfying smaller reward that requires less cognitive control, or a reward that has a higher long-term value but involves some impulse control (eg, I’ll give you $10 now Or transfer $50 to your bank) open an account tomorrow).
The results show that after people spend a long time thinking hard, the accumulation of glutamate triggers a response in the brain that makes it more difficult for us to use the prefrontal cortex (the area of the brain that allows us to control our thoughts), so our study said, Make more impulsive choices than strategy. After a long day, with less control over selection, glutamate is less likely to continue to accumulate to potentially toxic levels.
If you’re about to make an important decision or try to avoid heavy household chores, it’s important to make sure you’re not getting too tired, says study author Antonius Wiehler, a cognitive neuroscientist and postdoctoral researcher at the Paris Institute for Brain Research.
But here’s the bad news: According to the study, it may also be difficult for people to accurately measure how tired they actually are.
take a break and try new things
To learn how to overcome cognitive fatigue, we first need to recognize when it happens.
You’re less likely to experience cognitive fatigue from activities you enjoy than activities you don’t enjoy, says Philip Ackerman, a professor of psychology at the Georgia Institute of Technology. Ackerman was not involved in the study.
He adds that after 30 minutes of reading a textbook, you might feel much more mentally exhausted than if you stayed up late reading a novel.
That said, according to Ackerman, if you do anything that requires mental energy long enough, you’re likely to get fatigued.
Sometimes long hours of hard thinking cannot be avoided, and you have to play to the best of your ability. In these situations, how you deal with cognitive fatigue can make a big difference, Ackerman said.
“Feeling tired is not the same as declining performance,” he said.
People tend to have three responses to feelings of exhaustion: keep moving with less effort, focus on overcoming stress, or think harder.
The first option, he said, is often associated with decreased performance because there is less focus and effort on the task without a break to actually recover. The third can help you think and focus, but if you have to hold on for a long time, you risk breaking down badly. The second usually maintains a similar or even higher level of performance on a timeline of focused thinking, he added.
At best, people can avoid cognitive fatigue by establishing breaks during difficult thinking, Ackerman said.
These breaks can give a tired brain a break if they involve doing different activities. Even if it involves other things that require effort, changing things can help rejuvenate a tired mind, he says.
That means it might be helpful to end a day of intense research with a game of poker with friends or a walk outside. Taking time off could mean you get something better out of it when you get back to work.
Real rest helps, too, says Pessiglione.
“I’ll take the good old recipe: rest and sleep! There’s good evidence that glutamate is eliminated from synapses during sleep,” he said in a press release.