Compared to adults, children learn quickly, and their developing brains absorb information at an astonishing pace. Somehow, their neurons not only incorporate new knowledge more easily, they retain it, even in a constant stream of new experiences.
Now a team of neuroscientists from the University of Regensburg in Germany and Brown University in the US may have discovered what makes young brains so efficient.
It’s all down to a brain chemical known as GABA (gamma-aminobutyric acid) that increases in children during and after learning, turning their young brains into “ubersponges”.
“It is often assumed that children learn more efficiently than adults, although scientific support for this assumption has been tenuous at best,” said study co-author Takeo Watanabe, a cognitive psychologist at Brown University.
In search of the brain mechanisms involved, the team used an advanced neuroimaging technique called functional MRS (fMRS) to indirectly measure concentrations of GABA in the visual cortex of children during a visual learning activity to see how it differed from adults.
Measurements were taken on 55 children aged 8 to 11 years and 56 adults aged 18 to 35 years, covering three different periods: before the visual learning task started, during the learning process and after the activity had ended.
The results showed that GABA levels in adults remained consistent throughout the experiment. Meanwhile, GABA levels in children were much more adventurous.
“What we found is a rapid increase in GABA in children, associated with learning,” says Watanabe. And not just during learning – the high levels of GABA also lasted into the post-learning period.
It is a revealing discovery, says Watanabe.
GABA is a chemical messenger in the brain known to be important in the process of learning new information. It also plays a key role in stabilization, a “cooling off” period after learning where the fragile new neural networks are consolidated and the information is successfully stored.
But if something new is learned during the cool-down period, a phenomenon called ‘retrograde interference’ starts, where the previously learned information is overridden or destroyed – it slips out of our brain.
Think of it like letting a pie cool after taking it out of the oven. Resting gives the starch in the filling a chance to set into a gel that holds everything nicely in place. However, if you cut into the pie during the cooling period, the piping hot filling will become runny and ooze out.
With the new knowledge of GABA levels in children on board, the team conducted behavioral experiments to see if this was what allowed visual learning to stabilize more quickly. What they found was astounding.
Adults required a “cooling off” period of one hour to allow stabilization. But the children were able to learn again within 10 minutes without overriding what they had previously learned. In other words, thanks to their high GABA levels, their pie hardens much faster.
“We found that resistance to retrograde interference and therefore stabilization actually occurred within minutes after training ended in children, whereas learning was in a fragile state in adults for at least an hour after training,” the researchers wrote in their paper.
“This rapid stabilization of learning in children enables them to learn more things within a given period of time and makes learning more efficient in children than in adults,” explains psychologist and cognitive neuroscientist Sebastian Frank, a co-author of the study now at the University of Regensburg in Germany.
The researchers also found that subsequent sessions of learning appeared to further increase GABA concentrations in children, allowing for even faster stabilization of previous learning.
“Our results therefore point to GABA as a key player in making learning effective in children,” says Frank.
While it should be noted that this study was done in visual learning, Watanabe believes that these findings can be generalized to other types of learning that involve memory.
Excitingly, these findings can be used to help adults learn more effectively.
“For example, a new technology or therapy could be developed to increase the amount of GABA in the brain of adults,” says Watanabe. “There is a possible application.”
This research was published in Current Biology.