Children’s Brain Architecture Is Rewritten by Stress, Study Finds

This study showed that experiences a child goes through, such as poverty or family difficulties, can affect the development of brain connections, called white matter. When these connections are damaged, the child may have more difficulty with math and language in the future. However, having emotional support from people close to him or her can help protect the brain from these negative effects.

The human brain goes through a long process of development, especially during childhood and adolescence. This growth is deeply influenced by the experiences that the child has.

One of the most important elements in this process is white matter, which acts as a communication network within the brain, connecting different areas so that they can work together.

Despite its importance, we still do not fully understand how white matter participates in the connection between the environment in which a child grows up and their cognitive abilities in the future.

Many previous studies have focused more on changes in gray matter (responsible for information processing), leaving white matter in the background. This study, conducted by researchers at Harvard Medical School, USA, seeks to fill this gap by investigating how early life experiences affect the development of white matter and, consequently, cognitive abilities during adolescence.

In the study, researchers analyzed data from the Adolescent Brain Cognitive Development (ABCD) project, one of the largest studies ever conducted on the adolescent brain, with a sample of more than 9,000 children aged 9 and 10.

They examined the white matter of children who had experienced a variety of life experiences, including risk factors before birth (such as complications during pregnancy), family difficulties (such as violence or neglect), poverty and neighborhood problems (such as living in dangerous or under-resourced areas).

The scientists measured characteristics of the white matter using advanced imaging techniques, focusing specifically on a trait called fractional anisotropy (FA), which indicates the level of organization and integrity of fiber tracts in the brain.

The results showed that children exposed to these adversities had lower levels of fractional anisotropy in several regions of the brain’s white matter. This means that their brain connections were less developed or less efficient.

These types of changes have been linked to later difficulties in important skills, such as doing mental calculations (arithmetic) and understanding spoken language (receptive language). In other words, difficult experiences in childhood appear to affect the way the brain is organized and, as a result, can impair learning and school performance later in life.

Fractional anisotropy (FA) image

Another important point of the study is that it revealed that changes in white matter partially mediated the link between childhood adversity and later cognitive problems.

In simple terms, this means that part of the negative impact of difficult experiences on intelligence and learning occurs because these experiences disrupt the healthy development of connections in the brain.

These findings reinforce the idea that the development of white matter, which ensures communication between different brain areas, is crucial and occurs even before the full maturation of the better-known gray matter.

Finally, the study also had a positive message: it suggested that interpersonal resilience factors, such as support from close people, positive family relationships, and other sources of emotional support, can act as a buffer for the developing brain.

That is, even in difficult environments, social support can help preserve healthy white matter growth and improve children's cognitive outlook.

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Whole-brain white matter variation across childhood environments

Sofia Carozza, Isaiah Kletenik, Duncan Astle, Lee Schwamm and Amar Dhand

Proceedings of the National Academy of Sciences. 7 April 2025. 122 (15) e2409985122

DOI: 10.1073/pnas.2409985122

Abstract:

White matter develops over the course of childhood in an experience-dependent manner. However, its role in the relationship between the early environment and later cognition is unclear, in part due to focus on changes in specific gray matter regions. This study examines white matter differences across adolescents from diverse environments, evaluating both their extent throughout the brain and their contribution to cognitive outcomes. Using data from the Adolescent Brain Cognitive Development (ABCD) study (N = 9,082, female = 4,327), we found extensive cross-sectional associations with lower white matter fractional anisotropy (FA) and streamline count in the brains of 9- and 10-y-old children exposed to a range of experiences, including prenatal risk factors, interpersonal adversity, household economic deprivation, and neighborhood adversity. Lower values of FA were associated with later difficulties with mental arithmetic and receptive language. Furthermore, white matter FA partially mediated the detrimental relationship between adversity and cognition later in adolescence. These findings advance a white matter-based account of the neural and cognitive effects of adversity, which supports leading developmental theories that place interregional connectivity prior to gray matter maturation.