Ask HN: What data structure does our brain use? • Hacker News Board

Re: Ask HN: What data structure does our brain use?

#41

Post by gmt2027 » Sat, Oct 08, 2011, 3:02 PM UTC

Cushman wrote: post #34

gregdetre wrote: post #29

There are so many differences that one's standard intuitions as a computer scientist can be very misleading... I wrote on this elsewhere: http://blog.memrise.com/2011/05/how-is-memory-stored-in-brai... http://blog.memrise.com/2011/05/how-are-brains-different-fro... For instance: - Storage and parallel computation in the brain are very expansive and cheap, so the brain prefers to store rather than compute where it can…

What does it say about me that that all makes perfect intuitive sense? As computer scientists, we get really attached to binary logic because that's how computers work. I think sometimes it doesnt occur to us that it might not actually be the best way to model the universe.

Every time I write non-numerical code, it is fairly obvious that translation to this unnatural 'intermediate representation' requires extra effort.

Re: Ask HN: What data structure does our brain use?

#42

Post by gregdetre » Sat, Oct 08, 2011, 3:18 PM UTC

gmt2027 wrote: post #40

gregdetre wrote: post #29

There are so many differences that one's standard intuitions as a computer scientist can be very misleading... I wrote on this elsewhere: http://blog.memrise.com/2011/05/how-is-memory-stored-in-brai... http://blog.memrise.com/2011/05/how-are-brains-different-fro... For instance: - Storage and parallel computation in the brain are very expansive and cheap, so the brain prefers to store rather than compute where it can…

Can you distinguish between the storage schemes in short vs. long term memory? A transition takes place at some point. Long-term storage may not be the best indicator of actual structures used in working memory, which is where the computation actually happens. Also, content-addressability may be implemented fairly independently of the actual structure, that is an encoding problem that is analogous to an error correct…

Some forms of short-term storage are volatile, like RAM. They store by coaxing the neural activation into a stable attractor - as long as all the neurons keep firing in sequence, the memory stays alive. This is fast to create, since it doesn't require any hardware writes (changes in synaptic weights).

In contrast, long-term storage involves permanent changes in the synaptic weights between neurons, which survive any fluctuations in activation, and can then subtly influence computation ever after.

And for medium-term storage (from minutes to months, say), you have the hippocampus, which has a big hash table of pointers to long-term structures.

Of course, this is all a huge simplification :)

Re: Ask HN: What data structure does our brain use?

#43

Post by jtchang » Sat, Oct 08, 2011, 3:44 PM UTC

So many different answers. We really don't know much about how our brain really encodes the data and we are so far away from actually reproducing it. Scary when you think all of us have a copy of this memory structure.

Re: Ask HN: What data structure does our brain use?

#44

Post by zipdog » Sat, Oct 08, 2011, 3:56 PM UTC

It's worth noting that the brain changes as we learn - for e.g. when we learn maths the brain's structure is altered in discernable ways:

http://med.stanford.edu/ism/2011/june/math.html

So quite possibly the data storage used by a person with one particular upbrining/education would differ from a person with a different one.

In addition, different parts of the brain are likely storing data in different ways.

Re: Ask HN: What data structure does our brain use?

#45

Post by toadkick » Sat, Oct 08, 2011, 4:21 PM UTC

gmt2027 wrote: post #38

Cushman wrote: post #32

Earlier quoted context omitted.

How do you account for the fundamentally non-deterministic nature of the universe?

Actually representing the entire state of the universe sounds rather ambitious. However, the very action of 'imaging' will force the entire system into a consistent state by quantum collapse. The universe will be represented but changed, the original multitude of super-imposed states will be lost. Heisenberg's uncertainty principle implies that some things are just unknowable . However, only the most basic constituen…

This may be a nitpick, but how can something be "fairly deterministic"? Is it possible for there to be degrees of determinism? I would consider determinism to binary, either something is deterministic, or it is not. If a thing cannot be demonstrated to be deterministic 100% of the time, then by it's very definition it is non-deterministic. By that logic, I would actually conclude that the entire universe does in fact behave deterministically. If it didn't, then I don't see how science would even be possible.

Re: Ask HN: What data structure does our brain use?

#46

Post by Dn_Ab » Sat, Oct 08, 2011, 4:27 PM UTC

shasta wrote: post #24

gmt2027 wrote: post #14

Short answer: A graph. All data structures are simplified graphs. The state of the physical universe is a massive graph in which interconnected objects are themselves massive assemblies of graphs of atoms and the atoms are graphs of subatomic particles. It's graphs all the way down. The properties of all systems - physical, chemical, economic, biological - emerge from the interactions between simple connected element…

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.

A correction. A relation is not a function but a function is a relation. A function is a restriction of a relation such that for each thing_a in A and thing_b in B, for a pairing of (thing_a's,thing_b's) by some relation f,each thing_a can only be paired with one thing_b in B.

Re: Ask HN: What data structure does our brain use?

#47

Post by rmz » Sat, Oct 08, 2011, 4:29 PM UTC

kandu wrote: post #20

The right response is that science doesn't know yet.

Well, yes. Science doesn't know, but that doesn't mean that scientists doesn't speculate, or that some of those speculations may at some point be shown to be more or less correct. Not knowing in a scientific way is a very interesting kind of "not knowing" :-)