Ask HN: What data structure does our brain use?

Yes, isn't our conception of data structures bound up fairly tightly with the available storage media and data buses? We have thought a lot about how to organize and retrieve data on tapes, and spinning disks, and random-access memories composed of discrete little bins, each storing a bit and addressed in rows and columns.

But we don't make extensive use of (say) analog computers, or computers with data buses having several million sub-channels. Hand us a machine employing such principles and it's back to square one. (Except for the lucky pure mathematician or two who got there first but whose work remains obscure right now, the way George Boole's work used to be obscure.)

And my stupid examples are just examples - I have no idea if the brain, or any bit of it, is best conceived of as an analog computer. Nobody knows what kind of computer the brain is like, except that it is almost entirely unlike the silicon-based digital computers that we build in the von Neumann tradition. And, presumably, when it comes time to discuss brain-based data structures they will turn out almost entirely unlike the structures in our digital-computer-data-structures textbooks.

And a graph is a relation, and a relation is a function, etc. Just because you can model everything with graphs doesn't make them special. You can model everything with lots of things.

I think long term memory is more organized than a hash table. I base this on observation of my own brain during a bad LSD trip, where I seemed to be aware of how I was reaching decisions.

For example, if I looked at a door and wanted to remember what that door was for, I could "see" a vast 2 or 3 dimensional array of hundreds of doors that I had seen before, arranged so that similar doors were near each other, and then I was aware of some kind of focusing in on the region of door-space where doors similar to the target door resided, and then I was aware of some kind of comparison of each of the doors in that region serially with the door I was looking at to find a match, and then the data for the best match was made available to my normal consciousness.

During another part of that trip I was aware of audio processing. I'd hear someone talking and first hear it as unintelligible sound, then I'd be aware of the sounds being broken down into separate sound units, and then recognized as English words, and then the relationships between the words being recognized, and then I'd become aware of the meaning of what I'd heard.

I also had a time during that trip where I was watching visual processing. I'd be aware of how my mind was noticing things in the scene I was looking at, recognizing objects and remembering what they were, and combining that to build an understanding of the scene.

Now I have no way of knowing how much of this was just hallucinations shaped by my knowledge of computers, and how much really was the LSD actually letting me observe consciously mental processes that normally operate as black boxes to the conscious.

It's too bad research using LSD was greatly curtailed when the drug was banned. My suspicion is that what I perceived on that trip was a mix of reality and hallucinations driven by my computer knowledge. With enough experimentation, with people with different backgrounds observing and reporting, we could probably get some real insights into what is really going on in there.

Along a similar subject, should we someday be able to replace sets of neurons in our brains with nanomachines (built to replicate neurons), would we be able to replicate these data structures? Or are they something intrinsic to our organic brain? Similarly, if we could build even a larger scale version of such external to the brain, could we interface it with our existing consciousness? (Could we then 'share' memories?)

Working backwards from this, could we build (today) a graph-based (or whatever-structure) recording device that will store data in much the same way we build memories? Such would obviously require a greater understanding of the interconnection of neurons and the storage of memory, as discussed elsewhere in this topic. [Small edit: Knowing the data structure is nice; being able to use it is golden.]

I personally believe the next great "hack" our species should embark upon is the brain and the body. We need to be more robust if we are ever to escape this rock. (And the dreamer in me wishes we could keep our consciousnesses and/or memories around eternally, but that introduces entirely different problems, and is probably an unrealistic ideal.)

It's also very, very high-dimensional. Imagine a gigantic space, where similar thoughts could be placed next to one another. Thinking would be moving around this space. Free association would be taking a step or two in a random direction. Comparison would be a vector.

This captures a little of the nature of semantic representations (storage of meanings and concepts). But of course, semantic representations differ hugely from, say, representations of a tennis serve, or the phone number you're repeating under your breath while you key it in...