Hippocampus as Gateway

Every new explicit memory passes through the hippocampus — a seahorse-shaped structure deep in the temporal lobe. The most famous proof came from Henry Molaison, whose hippocampi were surgically removed in 1953 to treat epilepsy. For the remaining 55 years of his life, he could not form a single new conscious memory lasting more than 30 seconds. Yet he could learn new motor skills, proving different memory types use different brain systems.

The hippocampus is a gateway, not a warehouse. It processes and transfers memories to the neocortex over days to weeks. This is why brain damage typically destroys recent memories while leaving old ones intact — older memories have already graduated from hippocampal dependence.