Actually, if The Asmo may..?
I’m fascinated with the physiological workings of human “cold storage,” which, I assume, is what remote memory is (as opposed to me accessing your memories remotely, which, by the way, is also way cool)
How does it work? Is it the way the neurons are combined? A “physical map” of a memory, one might say? Or is our archive an active, electrochemical thing, what “surfaces” into the conscious due to some triggers? Or maybe both/neither? I don’t expect that we have all, or even many of the answers, but...
Do please feel free to pile very thick and convoluted literature upon me if this is not explainable in a reasonable forum post. :-)
A bit of both, I would say, though finding the precise physical substrate of memory, of the
engram, as it's called, is still frontier stuff. Huge leaps have been made in the last decade since the
optogenetic method was developed, which can essentially label populations of neurons and turn memories on and off just as easily as flipping a light switch. It's a much 'cleaner' method than pharmacologically inactivating a brain region, but expensive, a little too expensive for most labs in developing countries.
(then these lousy politicians who don't want to invest in science wonder why we're falling so behind, but anyways...)
It's believed that a memory trace comes from both the
physical organisation of neurons into networks and the
strength of connections between neurons. It takes a few hours to consolidate a memory at celular levels (synaptic consolidation - cells), and days, months and even years at the systemic level in the case of humans (systemic consolidation - circuits), though not all types of memories undergo this latter type of consolidation.
There are currently three major hypotheses that attempt to explain what happens as memories become systemically consolidated, the
Standard Model, the
Multiple Trace Theory and the updated version,
Trace Transformation Theory. In all, the hippocampus, which is a stucture located in the medial temporal lobe more or less between the ears in humans, is responsible for forming memories. You remove that structure and you will have access to some remote memories, but will be incapable of acquiring new ones. In Alzheimer's for instance, the hippocampus is one of the first structures to suffer damage, which is one of the reasons sufferers often regress back to ancient memories, such as when they were a child, etc.
There is still no consensus on which should be the prevailing theory, so it's still a little fuzzy. Also frontier stuff.
I won't go into minute details, but the main idea in all of them is that memories start in the hippocampus and "migrate" to cortical structures with time. That's basically what systems consolidation is about. The hippocampus goes offline and is not important in the recall of remote memories (according to the Standard model) but it still participates (according to the two others).
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