Brain Activity is Increasingly Variable During Development

Fluctuations in brain activity, also known as neural variability, enable us to be flexible in adjusting our behavior to the current situation. A new study shows that neural variability increases throughout development before stabilizing in adolescence. And deviating from this trajectory is associated with worse executive functioning, researchers found.

The study was published Sept. 17 in Neuron¹.

During development, individuals are exposed to many new experiences. Increasing neural variability during this period may support functioning as young people navigate evolving environments.

“There is a possibility that we are becoming more and more flexible at the neural level so we can better respond to all these different experiences that are happening to us during development,” says Jean Ye, a PhD student in the Interdepartmental Neuroscience Program at Yale School of Medicine (YSM) and the study’s first author.

The brain has a consistent developmental trajectory

Previous research on neural variability has often focused on a particular brain region or network. In their new study, Ye and her colleagues wanted to look at activation patterns across the whole brain.

The researchers analyzed four neurodevelopmental datasets to track how participants engaged these recurring brain activation patterns over time. The researchers focused on fluctuations in the patterns that were engaged and how those fluctuations changed with age. Across all datasets, they discovered a consistent developmental trajectory.

The researchers also used machine learning to build a model for predicting an individual’s executive function—which includes working memory and cognitive control—based on their neural variability. Then, they studied how deviations from the typical developmental trajectory related to executive function.

“Deviations in neural variability development were related to worse executive function,” says senior author Dustin Scheinost, PhD, associate director of biomedical imaging technology at the Yale Biomedical Imaging Institute. What specific functions are most affected still needs to be explored in future research.

The researchers plan to explore how deviations from the trajectory might coincide with symptom onset for various psychological conditions that tend to arise during development, such as depression and anxiety.

Ye is also interested in how factors like stress might influence neural variability and whether neural variability continues evolving over one’s lifespan. Aging individuals, for example, tend to have worse executive function compared to their younger counterparts.

“One possibility is that variability might fall down over time, contributing to people becoming less flexible,” poses Ye. “That’s something to explore in future research.”

Reference:

1. https://www.cell.com/neuron/abstract/S0896-6273(25)00629-4

(Newswise/VK)