The young and old have different brain waves, even doing the same task.

In Aging, Brain Circuitry, Brain Science, Memory and Learning by Brainy Days Ahead

“Fully understanding how we make and recall memories as we age has been a mystery,” This research shows that younger and older adults show very different brain wave patterns when performing the same memory task. “By mapping these key differences, we may be able to identify new ways to predict, diagnose and screen for cognitive decline.”