Older adults with above average memory skills for their age—so-called cognitive "superagers"—have distinct differences in brain networks compared to their cognitively normal peers. NIA-funded researchers identified two brain network regions that remain robust in superagers, and may enable them to perform on memory tests as well as middle-aged people, and even young adults.
Brain atrophy, characterized by a loss in cortical thickness, is common with aging. Researchers led by Dr. Brad Dickerson at Massachusetts General Hospital and Harvard Medical School, Boston, explored these brain volume differences in superagers, in part to discover whether cortical thickness in older people could predict memory performance. Their findings were published in the Sept. 14, 2016 issue of the Journal of Neuroscience.
In the study, 41 young volunteers (mean age mid-20s) and 40 older participants (mean age mid-to-late 60s) underwent memory testing and magnetic resonance imaging (MRIs) to measure brain volume. Based on the memory tests, researchers identified 17 superagers. Compared to their peers, the superagers showed little to no loss of cortical volume of brain regions within the default mode and salience networks that are important to memory storage, attention, encoding and retrieval. Notably, in some superagers, these regions were so well preserved that they were indistinguishable from the young volunteers. The researchers also found that the hippocampus—a brain region important to learning and memory—was well preserved in the superagers.
More research is needed to better understand the factors that may lead to resilience against age-related cognitive decline in people with above average memories as they age. Additional studies could also elucidate whether and how memory and cortical thickness in cognitive superagers change over time.
Sun, F.W., et al. Youthful Brains in Older Adults: Preserved Neuroanatomy in the Default Mode and Salience Networks Contributes to Youthful Memory in Superaging. Journal of Neuroscience. Sept. 14, 2016. 10.1523/JNEUROSCI.1492-16.2016