[sykic]

I’m a mathematician and tend to take things literally. I should not have mentioned the infinite tape part. What I should have said is that according to the article we don’t store memories in the way that a Turing machine does. There is no tape as such and there is no set of rules that the brains abides in terms of how to do the next step so to speak.

I gathered that the quote I referenced means that the state of a brain at time t is not sufficient to reconstruct memories or other meaningful information. The fundamental point of contention between you and others criticizing the article appears to be that you all believe that there is a storage mechanism in the brain in a similar (analogous?) fashion as a computer. I gather the author claims this is not so. Information is not stored in neurons in such a way that one “retrieves” it by accessing a storage location.

I don’t know enough about this stuff to intelligently comment on the veracity of it. I just know that someone far more knowledgeable than me and just about everyone else commenting says that our intuition about how this stuff works is wrong. That alone is worth causing me to reconsider my intuition on this stuff.

[mannykannot]

Speaking for myself (I don't necessarily agree with everything that has been said in opposition to this article), I think you are missing my point about memory.

The author is saying our brains do not function like our digital computers, something I think we do all agree on. It is not so clear how the author thinks our brains do work, but he apparently wants us to stop using computer metaphors when discussing their function.

He would have this prohibition extend to the notion that our brains store and retrieve information, which is absurd; one might as well argue that a computer is not a Turing-equivalent device because RAM is not a tape. The author says that scientists will never find copies of words or grammatical rules in the brain, and if, by copies, he means coded in something like UTF-8, then that is, of course, true, but beside the point: if his brain did not have some mechanism that supports the storage and retrieval of this information in some manner, how was he able to write the article in the first place? He claims you won't find copies of Beethoven's 5th. symphony in a brain, but I suspect that at least Beethoven himself, and many conductors of the piece, have had just that - and the soloists who play his piano concertos are not reading from a score, so where does that come from?

I think the author may have ended up making these absurd claims because he is trying to use the trivial brain-does-not-function-like-a-computer argument to prove something that is just an unargued-for intuition: he doesn't seem to think RAM (or perhaps any form of physical information store) could possibly be the foundation for something that works like human memory. He is apparently unaware of the extent that software such as neural networks (or even relational databases) have already extended the concept of information storage and retrieval beyond the simple model of randomly-addressable bytes (which does not, of course, make the point that human memory is like a computer's; what it does show is that the author's low-level comparisons are insufficient to make the larger point he is trying to squeeze out of them.)

[sykic]

My take on the article and in particular the quote that I referenced in my original post is that the author does not think memory is stored in the way that you and I think it is. The way I think of the brain working with regard to memory is analogous to how computers store information. I’m unable to model it in any other way. But then there’s the quote in the article that even if I had a snapshot of the brain at time t I would not be able to reconstruct something meaningful without knowing the history of that brain’s owner.

I don’t know enough to understand how that is possible or why someone knowledgeable about this stuff thinks this. I have basically the same conception of the brain and how it works as you do. But I’m confronted with the fact that a person far more knowledgeable than me thinks otherwise. It is that fact that causes me to persist in my view with caution. The author may be a crank. I don’t know.

[russdill]

This seems like a really fine distinction, but it's more of an unbounded tape rather than an infinite tape. The tape can only reach infinite length after infinite time.

[mannykannot]

True, but for a finite-tape machine, the possible outcomes include 'ran out of tape'. Also, for any finite-tape machine, there is a finite-tape machine that computes whether the first halts, runs out of tape, or runs forever.