Deep sleep could forestall the declines in brain health that can eventually lead to Alzheimer's disease, the most common form of dementia. In their study of 62 older, cognitively healthy adults, researchers from the University of California, Berkeley, Stanford University, and UC Irvine in the US found that individuals with brain changes associated with Alzheimer's performed better on memory function tests as they got more deep sleep. This was independent of education and physical activity, two