Have you ever wondered why thinking too much makes you tired? A new study has found some answers to this question. Researchers the Paris Brain Institute looked why mental effort makes us tired. They found that when people think a lot, the brain releases a chemical called glutamate. Too much glutamate upsets the brain's functions. It means the brain tells the body it is tired and that it must rest. People who spend more than six hours working a task that requires a lot thought are more likely to feel tired. A period rest allows the brain to return to normal. This explains why a power nap is good us. A power nap can be as short as 20 minutes, but can make us feel totally refreshed.
The research team looked the behaviour 40 participants their research. Twenty-four of these had to perform challenging tasks. These included looking a computer screen and matching different letters that appeared. The other 16 participants did a similar, but easier task. Both teams worked six hours, and had two ten-minute breaks. The researchers scanned the brains the participants. They found that the group who had the more difficult task had higher levels glutamate their brain. Study author Antonius Wiehler said: "It would be great to find more about how glutamate levels are restored." He asked: "Is sleep helpful? How long do breaks need to be to have a positive effect?"
