PanARMENIAN.Net - Functional regions within the brain become less distinct and inter-connected in the elderly over time, especially in those networks related to attention span and cognition. The finding, published by researchers at Duke-NUS Medical School in The Journal of Neuroscience, adds to current understanding of longitudinal decline in brain network integrity associated with aging.
"We currently live in a rapidly aging society. Compared to cross-sectional studies, it is vital to understand brain changes over time that underlie both healthy and pathologic aging, in order to inform efforts to slow down cognitive aging," said the study's corresponding author, Associate Professor Juan Helen Zhou, neuroscientist from the faculty of Duke-NUS' Neuroscience and Behavioral Disorders program.
The human brain contains functionally segregated neuronal networks with dense internal connections and sparse inter-connectivity. Aging is thought to be associated with reduced functional specialization and segregation of these brain networks.
Joint senior authors Assoc Prof Zhou and Prof Michael Chee, Director of Duke-NUS' Centre for Cognitive Neuroscience, led the research team, collecting data from neuropsychological assessments and functional magnetic resonance imaging (fMRI) brain scans from a cohort of 57 healthy young adults and 72 healthy elderly Singaporeans. Each elderly participant was scanned two to three times during a period of up to four years. The neuropsychological assessments tested participants' ability to process information quickly, focus their attention, remember verbal and visuo-spatial information, and plan and execute tasks. The fMRI scans measured how brain regions are functionally connected based on low-frequency blood oxygenation level fluctuations over time. Participants were asked to relax with their eyes open and remain still as these were performed.
Dr Joanna Chong, first author of the paper and a PhD graduate from Assoc Prof Zhou's lab at Duke-NUS, developed approaches to convert the fMRI images into graphic representations that depict the inter- and intra-network connectedness of each individual's brain. She then compared differences in brain functional ne...
