Each night, the sleeping brain is engaged in a quiet act of maintenance — and a University of Arizona study of more than 23,000 adults suggests that how we sleep may leave a legible record in the brain's tissue long before any symptoms appear. Published in Alzheimer's & Dementia, the research found that three common sleep behaviors — sleeping outside the recommended seven-to-nine-hour window, frequent daytime napping, and chronic sleeplessness — each independently correlate with greater volumes of white matter lesions, microscopic markers of brain aging linked to dementia risk. The findings ar