Genes shape how your brain responds to the world
Two people watch the same film. Their brains respond differently. New research shows that genes largely determine how your brain processes information, and that this is relevant for understanding brain aging.
Researchers used 7-Tesla fMRI scans from a large group of twins to measure how heritable brain activity is when people watch movies. The study, published in eLife, showed that brain responses to complex audiovisual stimuli are highly heritable across the cortex. Heritability was strongest for information processed at low temporal frequencies, and more pronounced in associative brain areas than in primary sensory regions.
The researchers went beyond simply establishing heritability. They decomposed it into two components: where in the brain information is processed, and how it is processed. Both turned out to be genetically determined. They also found that the heritability of brain activity patterns is partly explained by the heritability of the neural timescale, a measure of how long a local brain circuit remains active after receiving a stimulus.
What neural timescales reveal about aging
The neural timescale is relevant to aging research. As people grow older, local brain circuits change in how long they stay active. Deviations in the neural timescale have previously been linked to cognitive decline and neurodegenerative conditions. This study shows that the timescale itself is heritable, implying that genetic variation partly determines how vulnerable a person’s brain is to these age-related changes.
The finding that functional brain connectivity (the degree to which brain regions work together) is also heritable and follows the same pattern strengthens this picture. From a longevity perspective, this matters: individual biological blueprints play a role in how the brain ages, independent of lifestyle factors.
Limits of this research
The study worked with healthy adults and did not directly investigate disease or decline. The link to cognitive aging remains interpretive for now. Whether the heritability estimates hold in older or clinical populations has not yet been examined. The findings do offer a new framework for future studies on genetic risk factors for brain aging.
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