as older adults begin to move and explore less than, say, young or middle-aged adults, those hippocampal-based memory systems might atrophy—use it or lose it, as the professional athletes say. The central role that the hippocampus plays in general, not just in spatial memory, can additionally account for other cognitive impairments often seen in less active older adults—including decrements in reasoning, hand-eye coordination, and problem solving, as well as general cognitive slowing.
