“Our brain continues to develop longer than we thought,” states Ph.D. student Dorien van Blooijs.
According to recent findings from the University Medical Center Utrecht (UMC Utrecht), our brain’s decline occurs later than previously believed. The study, published in Nature Neuroscience, reveals that the decline occurs between the ages of 30 and 40, instead of after our 25th birthday.
Dorien van Blooijs, a clinical technologist, and Frans Leijten, a neurologist, collaborated with colleagues from both UMC Utrecht and the Mayo Clinic to conduct a study on the aging process of our brain’s processing speed.
The researchers discovered, among other things, that the connections in our brains become increasingly faster: from two meters per second in children aged four to four meters per second in people aged between thirty and forty. A doubling, in other words. Only after that age does it slow down. “Our brain continues to develop a lot longer than we thought,” Van Blooijs said.
The researchers also see differences between brain regions. The frontal lobe, the front part of our brain responsible for thinking and performing tasks, develops longer than an area responsible for movement. Van Blooijs explains, “We already knew this thanks to previous research, but now we have concrete data.” The development of speed is not a straight line, but rather a curve.
The researchers obtained the data by making precise measurements using an electrode grid that some epilepsy patients get placed on their brains (under the skull) in preparation for epilepsy surgery. The grid consists of 60-100 electrodes that can measure brain activity. “By stimulating the electrodes using short currents, we can see which brain areas respond abnormally. Thus, we can create a map of which areas should and should not be removed during epilepsy surgery,” Leijten said.
The fact that the data could also teach the researchers something about how our brain works was a new insight. “We have been collecting this data for about 20 years,” Leijten said. “It wasn’t until a few years ago that we realized we could use the unaffected areas as a model for the healthy human brain.”
Van Blooijs adds: “If you stimulate an electrode in one area, a reaction occurs in another. That lets you know the two areas are connected. You can then measure how long it takes for the reaction to occur. If you know the distance between the two different brain regions, you can calculate how fast the signal is transmitted.”
Better computer models
The results of this study provide important information about our central nervous system. Scientists have long been trying to map the connections in our brains. With this information, experts can make more realistic computer models of our brains.
For these models to work, in addition to information about the connections, precise values concerning the speed of those connections are needed. “We now have these numbers for the very first time,” Leijten explains, “With our data, researchers can make new and better computer models that increase our understanding of the brain. We expect our work to not only advance epilepsy research but also research into other brain disorders.”
Open to progress
With this publication in Nature Neuroscience, all data has become publicly accessible. This is called Open Science and it means that researchers from all over the world can use the data. Leijten: “By participating in research, patients contribute to progress. The knowledge we gain can be used to better treat future patients.” Van Blooijs will receive her doctorate at the end of this year. She says, “A lot is possible with this data, more than we can do. I’m curious to see what kind of research all the creative people around the world will come up with.”
Reference: “Developmental trajectory of transmission speed in the human brain” by Dorien van Blooijs, Max A. van den Boom, Jaap F. van der Aar, Geertjan M. Huiskamp, Giulio Castegnaro, Matteo Demuru, Willemiek J. E. M. Zweiphenning, Pieter van Eijsden, Kai J. Miller, Frans S. S. Leijten and Dora Hermes, 9 March 2023, Nature Neuroscience.