[aristofun]

Processing information is pretty vague and generic idea. You can label virtually anything as “processing information” and be more or less true.

But I doubt i find any neuroscientist worth anything who say “brain is doing computations almost like a computer”.

[plokiju]

Like I said, it depends very much on how you define computer. To me "processing information" == "computation". And a physical system that performs "computations" is a computer. Therefore, a brain is just one type of biological computer.

In a computer science class, the first thing they should teach is that the word "computer" in the course name is abstract, and not just about the metal slab on your desk. There are fundamental laws that apply to all information processing systems, whether electrical, mechanical, or biological. So it makes sense to put them in the same category at times.

But obviously words mean different things in different contexts, and "computer" might mean something entirely different to a neuroscientist than a computer scientist. But I don't think a neuroscientist would disagree that a brain is a computer using the loose definition I described above

[aristofun]

Of course, you can set up a definition space so that a puppy is a steam engine.

But if we stick to commonly adopted definitions, like https://en.wikipedia.org/wiki/Computer or "turing machine" ones - then NO, sorry, brain and computer has barely anything in common. Besides being made of atoms and being complex )

[plokiju]

So it sounds like we both agree the brain is at least a physical object that performs computations. I'm surprised you don't see similarities with other physical systems that perform computations, but sounds like a terminology difference

[aristofun]

Here is the heart of our disagreement:

> perform computations

Brain doesn’t perform computations in any CS accepted sense (neither it is a turing machine nor it has any encoded program to execute any defined algorithm).

It processes information, yes. But anything more specific than that is full of unknowns, unconfirmed hypothesis and speculations.

Would you call an ants colony a computer? A tree? A government? But they all obviously processes information and seemingly perform computations, don’t they?

[plokiju]

> Brain doesn’t perform computations in any CS accepted sense (neither it is a turing machine nor it has any encoded program to execute any defined algorithm).

That's a big statement. Anything that can be effectively described with math, can be described using Turing machines and algorithms. Any Turing-complete system is equivalent. As far as we know, all of physics can be described by equations, therefore is (theoretically) computable. What makes you think brains are special? Are there any other physical systems that you think are uncomputable?

The only arguments I've found for why the brain can't be described by algorithms go into unconvincing pseudo-scientific arguments about the magic of quantum mechanics, which I find very unconvincing (quantum algorithms are still algorithms, and describable through math after all). Do you have a better one?

> Would you call an ants colony a computer? A tree? A government? But they all obviously processes information and seemingly perform computations, don’t they?

Yes, absolutely. You can use ant colonies or slime molds as biological computers to solve real-world finding problems: https://www.youtube.com/watch?v=BZUQQmcR5-g&t=1s

Some of your other examples are more complicated, but all of them can be described through the computational lens, and modeled as Turing machines. you will find many scientific papers filled with equations trying to describe the algorithms behind each of them

[aristofun]

okay, we came to conclusion that almost any living organism can be called a computer

then what's the point in using this term if it doesn't differentiate anything?

it becomes meaningless, therefore there is no value in calling the brain a computer - it gives zero information about how brain actually works

case closed )