Do we understand how memory works in general? If you tell me to remember the number 71, I can do that instantly with my short term memory, so I would guess that works without any changes to the brain structure and more like charging or discharging the tiny capacity in a DRAM cell or flipping the feedback loop in an SRAM cell. For long term memory on the other hand I would assume that this involves changes to the brain structure as this seems more robust but slower to do, I would have to think of 71 for quite some time in order to remember it weeks, months or years later. Do we know anything about this in good detail or is this still too hard to investigate because the relevant structures or processes are hidden in a sea of other things?
We don't really know much about how memories are formed, the short-term and long-term divisions come from cognitive psychology and we don't have (from what I remember from my neuro days, which may be out of date by now but I am friends with several neuroscientists and I'm not sure it's out of date yet) a strong idea of what the biological correlates of each are, or even if they arise via different processes or what.
