My take is that the hippocampus remembers the key features of your experience; the most processed version of the day’s events. At night, during REM sleep, the contents of the hippocampus is replayed reinforcing the memories of the day.
Some hippocampus factoids in no particular order:
- The hippocampus seems to hold about 1 days worth of experience before saturating. Symptoms of saturation include discomfort and hallucinations.
- From a system approach - the buffered events of the day allow the amygdala and other sub-cortical structures to add emotional weighting to the memories before consolidation in sleep cycles.
- It is likely that the hippocampus does good one-shot episodic learning as opposed to slower Hebbian learning in the cortex. It is possible that sleep spindles power an accelerated learning in the cortex.
- The sleep cycles seem to normalize or reset the hippocampus for a new days learning. If the hippocampus is learning the “delta” between what is in the cortex and hippocampus I could see that part of the process is to “ring” both to test the response and drive learning to the cortex until they are in agreement.
- The claims that spatial processing is done in the hippocampus seems off - patients with damage to the hippocampus see to be able to process space normally - they just can’t form new memories.