The data provided a baseline against which the model could measure “local brain age,” or how old specific regions of the brain appear. “Not all brain regions age at the same rate,” Irimia said. By measuring local brain aging, we can identify where the brain is aging faster than expected and how those changes relate to cognitive function.” Brain age as a biomarkerThe research builds on previous efforts to estimate brain age, an emerging neuroimaging biomarker that compares a person’s brain structure to patterns seen in healthy people across the lifespan. The new approach instead measures local brain age at the voxel level — the three-dimensional units that make up an MRI scan — producing a much more detailed picture of structural aging throughout the brain.