Max Planck Society-University College London Initiative for Computational Psychiatry and Aging Research (ICPAR); Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
Neuroscientists have long observed that brain activity is naturally variable from moment-to-moment, yet neuroimaging research has rarely considered signal variability as a within-person measure of interest. Our fMRI work on younger and older adults suggests that within-person BOLD signal variability offers highly predictive, complementary, and even orthogonal views of brain function compared to traditional mean-based measures. In particular, we continue to find that older, poorer performing adult brains often exhibit less signal variability, within and across brain regions and tasks. Accordingly, I will discuss the idea that contrary to traditional theoretical expectations of adult-developmental increases in “neural noise,” brain aging could instead be re-conceived of as a generalized process of increasing system rigidity and loss of dynamic range.