For decades, we’ve thought that memories were formed in two distinct stages—short-term first, then long-term later.
We might be wrong.
New research suggests that our brains make two copies of each memory in the moment they are formed. One is filed away in the hippocampus, the center of short-term memories, while the other is stored in cortex, where our long-term memories reside.
.. After a brain surgery to treat his epilepsy damaged his hippocampus, he could no longer form new memories. But those memories he made before his surgery still existed, leading neuroscientists to believe that the hippocampus was key to forming new memories.
.. For the first few days, though, the neurons in the hippocampus are the only ones that fire during memory retrieval. Eventually, the memories in the cortex mature, and the neurons involved light up when the memory is recalled.