It is not only pupils and students who know that those who concentrate intensively for a longer period of time usually get tired. Researchers have now found a reason why this might be the case. During intensive cognitive work lasting several hours, glutamate accumulates in one part of the brain.
The neurotransmitter glutamate therefore accumulates in the area of the brain known as the prefrontal cortex. The area is active when people are planning something or solving complex problems, a research team led by Antonius Wiehler of the Pitie-Salpetriere Hospital in Paris said in the journal Current Biology.
The researchers write that the accumulation of glutamate causes cognitive fatigue. This leads to more relaxed activities that require no effort or waiting.
Molecules in the brain checked for research
The researchers used special techniques for their research that made it possible to monitor the concentrations of certain molecules in the brain several times a day. They examined two groups of subjects: one had to solve difficult tasks, the other was given relatively easy cognitive tasks. Result: At the end of the day, the demanding cognitive effort resulted in a higher concentration of glutamate in the said brain region than the light cognitive work.
According to neurophysicist Harald Möller of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, increases in the glutamate concentration of several percent have been observed in many cases when different areas of the brain are stimulated – for example the visual system. However, there was a relatively rapid drop in messenger substance when stimulation ended.
However, he is not convinced by the interpretation of the results in the French study. He criticized the conclusion that there was a sustained increase in glutamate in the intercellular space. However, it is difficult to make measurements on this part of the brain. Möller said the researchers also had to measure the resting phases of the subjects. Then they would have had a reference as to how the experiment affected the rise in glutamate — as opposed to a previous rest period.
Source: Krone
I’m Wayne Wickman, a professional journalist and author for Today Times Live. My specialty is covering global news and current events, offering readers a unique perspective on the world’s most pressing issues. I’m passionate about storytelling and helping people stay informed on the goings-on of our planet.
