Family environment affects adolescent brain development

https://www.eurekalert.org/pub_releases/2020-05/ki-fea052020.php

News Release 20-May-2020
Karolinska Institutet


Childhood environment and socioeconomic status affect cognitive ability and brain development during adolescence independently of genetic factors, researchers at Karolinska Institutet report in a new study published in the journal PNAS. The study demonstrates how important the family environment is, not just during early infancy but also throughout adolescence.

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At the age of 14, genes and environment were independently associated with cognitive ability (measured using working memory tests) and brain structure. The environmental effects were, however, 50 to 100 per cent stronger than the genetic. Differences in socioeconomic status were related to differences in the total surface area of the neocortex.

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Genetic differences were also linked to brain structure, affecting not only the brain's total area but also specifically an area of the right parietal lobe known to be important for mathematical skills, reasoning and working memory. This is the first time a brain area has been identified that is linked to this genetic index.

When the researchers followed up on the teenagers five years later, they were able to examine how genes and environment had affected the brain's development during adolescence. What they discovered was that while the genes did not explain any of the cerebral changes, the environment did. However, it is unknown which aspect of the environment is responsible for this.

"There are a number of possible explanations, such as chronic stress, diet or intellectual stimulation, but the study shows just how important the environment is, not only during early childhood," says principal investigator Torkel Klingberg, professor of Cognitive Neuroscience at the Department of Neuroscience, Karolinska Institutet. "Finding the most important environmental factors for optimising childhood and adolescent development is a matter for future research."