Hard physical work makes us tired, but what about hard mental work? The American writer Wallace D. Wattles once claimed the following in the 19th century: “Thinking is the hardest and most exhausting of all work…” And perhaps he was absolutely right. At least if we are to believe the results of a new European study. Here, researchers have found that there is a link between mental fatigue and negative changes in our brain. The study is published in Current Biology. The chemistry in the brain changed With a desire to understand the underlying cause of mental fatigue, researchers from Switzerland and France recently conducted an experiment. They divided 40 people into two different groups. One consisted of people working on challenging tasks, which required a great deal of thinking. The other group solved relatively simple cognitive tasks. Using a method called MRS, the researchers analyzed the chemistry in the brains of the participants. The results showed, among other things, that people who spent more than six hours on difficult tasks had higher levels of glutamate in the brain. Glutamate is a signaling substance, and high values of this can disrupt various functions. The toxic by-products build up in the part of the brain we call the prefrontal cortex (the thinking brain). Disproves old theories – Previous theories have suggested that this mental fatigue is some kind of illusion shaped by our brain. That this makes us stop what we are doing, so that we can rather focus on something positive, says Mathias Pessiglione. He is a researcher at Pitié-Salpêtrière University in Paris. – But our findings show that cognitive work actually results in a real functional change. A formation of harmful substances. He therefore believes that this fatigue is rather a signal that makes us stop working because our brain needs rest. So that it can function optimally again. Rest should, among other things, be essential to restore the correct levels of glutamate. As an example in their study, the researchers use professional chess players. – Discharged and empty When you have completed a real training session, it is easy to see that the efforts have taken off. The flowing sweat is quite revealing. When someone says they are mentally tired, you almost have to believe they are telling the truth. There is little visible evidence. Or? If you study chess players, you can perhaps see the hint. In the study, the authors write that professional chess players more often make mistakes four to five hours into the game. These are mistakes they would rarely have made if they were rested. – Long, demanding games definitely make me tired, I think most chess players have known that. That’s what Joachim B. Nilsen says to news. He is president of the Norwegian Chess Association. Joachim B. Nilsen thinks the new research is exciting. But even though chess is demanding, he believes the game has positive effects in terms of ability to concentrate and strategic thinking. Photo: Norges Sjakkforbund Classical chess in particular is demanding, it’s a bit like having an exam, says Nilsen. – The game requires concentration. It is good training in terms of tactics, strategy and memory, and can thus stimulate several areas of the brain. However, it requires concentration to play at your best for a long game or an entire tournament. The professional chess player describes the feeling of mental fatigue as a kind of discharge, that one becomes a little empty and exhausted. – It is probably mostly after the party that I personally feel this feeling. Along the way, it is not unusual to become so engrossed in the game that you can forget both time and place. Can mental endurance be improved? The researchers behind the new study believe that this is an important aspect to study, but they do not want to draw any conclusions yet. Now they hope studies on animals can help them a step further. Neuroscientist Antonius Wiehler has participated in the study. He hopes they can get better answers on how to quickly recover from mental exhaustion. – It would be great to find out more about how glutamate levels are restored. Is sleep useful? And how long must the breaks be to have a positive effect? None of the researchers believe that mental endurance can be improved, but that proper rest means that you can get back to the hooks faster. A game of chess can last for many hours, and as time passes, the players make more mistakes. Chess at the professional level is a huge cognitive load. Photo: Berit Roald / NTB scanpix
ttn-69
Researchers have found an explanation for why thinking hard makes us mentally tired – news Trøndelag
