Topographic distribution of brain connectivity profiles across different brain regions in similar age groups (left) and different age groups (right). Image credit: Zhang et al.
Brains can implement the same function in different ways. For example, across individuals, the same anatomical location may serve different roles, and the same functional region may vary in size, location, and shape. As a result, directly comparing anatomical locations across brains is like comparing apples to oranges.
To address this issue, researchers use a method called hyperalignment, which aligns brains functionally before analysis. This technique establishes correspondence across individuals by arranging their brains to a common template, allowing researchers to study both commonalities and individual differences in brain function.
However, certain brain features change over time and can be more prominent in some age groups. Zhang et al. sought to determine whether age-specific functional templates would be more accurate across age groups.
The researchers used preexisting fMRI data from people aged 18 to 87 to build age-specific templates and tested their performance on additional datasets. They found that hyperalignment templates derived from the same age group consistently outperformed those from other age groups by better capturing the functional brain organisation of individuals within the same age group and predicting brain responses. However, performance declined as the difference between a participant’s age and the template age increased.
In the long term, these findings may improve our ability to study the neural mechanisms of different populations, including individuals of different ages and those with neurological or psychiatric conditions. Population-specific templates could make brain mapping more sensitive, enabling better detection of group-specific functional features. While this study focuses on age differences, future work examining other populations will help establish the importance of building tailored templates for various conditions.
