How Does Matt Walker Connect Aging, Deep Sleep, and Alzheimer's?

Broken deep sleep tracks the memory loss. In Sleep Is Your Superpower on TED Talks Daily, Matt Walker says that as people age, learning and memory fade, and sleep gets worse, especially deep sleep. His group published evidence that the two are linked, and that disrupted deep sleep contributes to cognitive decline in aging. They have since seen the same pattern in Alzheimer's disease. He calls sleep a missing piece because, unlike changes in the structure of the brain, it might be treatable. He rejects sleeping pills as too blunt. His lab is testing direct-current brain stimulation to restore deep sleep in older adults and people with dementia, and to salvage some learning and memory.