
What the brain's wiring looks like - happy-go-lucky
http://www.bbc.com/news/health-40488545
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nacc
Just to clarify, these MRI images looks at white matter, which are mostly
bundles of long-range myelinated axons. This is more likely a map of major
highways in the brain (Or really the map of bundles of major highways in the
brain, as MRI only has millimeter resolution).

The connectome at the cellular level is massive. I think part of the mouse
visual cortical connectome has been mapped out, and the data is on the order
of tens of terabytes.

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nwjtkjn
This might be naive, but I wonder if the essential part of mouse data could be
compressed if only we understood it better.

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vilhelm_s
The mouse genome is only 160 megabytes, and contains the instructions for
building the brain as well as building everything else, so the "secret sauce"
of how to make an intelligent brain should not be extremely large, once you
figure out how to do it. :) A lot of the actual connections must be either
random, or encoding things the mouse learnt while growing up.

~~~
dunk010
Absolutely dead wrong. It's 2.5Gb, where Gb = Giga __bases __. Learn you a
genomics, son.

[https://www.nature.com/nature/journal/v420/n6915/full/nature...](https://www.nature.com/nature/journal/v420/n6915/full/nature01262.html)

~~~
Asooka
There are four bases, so one base encodes two bits of information. Eight bits
are one byte, so four bases are one byte. 2500 megabases = 625 megabytes. So
yeah, Parent was off by a factor of 5-6 :) . But still, that fits on one CD.

~~~
dunk010
Except that currently genomics requires even more information to be encoded -
such as quality scores, allele frequencies, phase information, ... - so,
depending on the format, this estimate is off by either one or two orders of
magnitude still.

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booleandilemma
Just wondering...

How complicated does a brain have to become in order to understand itself?

Could a brain exist that is so complicated that it could not understand
itself, or does a brain's understanding always scale up with its complexity?

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s-macke
You should first define what actually means "understanding the brain" before
you try to answer this question.

Does "understanding of the brain" mean, that we can construct or simulate a
brain? An artificial brain, which reproduce our intelligence and
consciousness?

There is no reason to believe, that we can't do this. A brain is part of our
world, governed by physics.

However, we will never be able to understand the thought process down to each
individual activation of the neuron.

That's like trying to "understand" and follow the movement of each atom in my
coffee next to me.

~~~
wu-ikkyu
>There is no reason to believe, that we can't do this. A brain is part of our
world, governed by physics.

How do you know consciousness is "governed" by our contemporary understanding
of physics?

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tux1968
It's not a question of our contemporary understanding being sufficient to
model a human brain. Rather it's that there is little or no reason to believe
the brain and consciousness are pure unassailable magic. So it should be
within the scope of future scientific understanding.

~~~
goatlover
The brain and consciousness need not be magic for the philosophical issue to
arise. The fundamental question is objectivity vs subjectivity. Consciousness
is subjective, yet science is an objective affair. Can the objective be used
to explain the subjective, or is the objective an abstraction from
intersubjective experiences?

If it's the latter, then the project to explain everything in scientific terms
is doomed, because it will always leave something out. If it's the former,
then subjectivity is not fundamental, but arises from the objective world. How
this is so is a difficult matter (no pun intended).

Either way, there is no magic involved, just a question of where philosophical
assumptions begin. You can start with matter or the mind and see where it
takes you.

~~~
tux1968
Either consciousness lives in the physical constructs of the human brain or it
is supernatural / "magic". If the first case is true, then there is every
reason to believe it is open to the scrutiny of the scientific process. What
we know for sure is that there are very many scientific questions about the
brain that still remain to be answered before we have to throw up our hands
and admit that it is all ineffable.

IMO science _is_ doomed to always leave something out as you say.. it will
reach a fundamental building block that simply exists, can not be expressed in
terms of something else and might as well be called God. But i just haven't
heard any convincing arguments that consciousness can't be understood before
we reach that point.

~~~
KennyCason
I don't think it's just your opinion. :) I think Godel and many other
logicians/mathematicians/philosophers would agree we are likely doomed to
"always leave something out", particularly in the sense that we will fail to
create "the perfect logic" that can explain everything. Oh the joys of living
"in the system".

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anotheryou
Looks like any MRI. I did this from scans of my brain and than tried to follow
the visual cortext to my eyes. I couldn't, because the scans only show the
general direction water flows in, but the nerves behind the eye cross and at
this point you can't tell what is just noise and what are interlaced nerves.

Would be interesting to know how much better this model is.

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psyq321
Just to clarify, MRI scanner at Cardiff is Siemens Connectom A, a specialized
research 3T MRI scanner for which the main designs were part of Human
Connectome Project.

It is not exactly "hot news", as it is already in research use for several
years already (in the US, at MGH). It is, still, however, pretty unique in a
way that it was optimized for human in-vivo diffusion MRI (tracing of white
matter pathways in alive human subjects :-).

Diffusion MRI scans which can be obtained by this scanner are of exceptionally
high quality and resolution (spatial and angular), and contain lots of data
that can be fed to mathematical models to infer fiber crossings, etc.

However, despite the high spatial and angular resolution it is still at least
an order of magnitude short of what is necessary to capture local axonal
connections and this type of imaging certainly does not tell you the direction
the signal is flowing.

Still an important progress IMO.

~~~
DrAwdeOccarim
It says it's 7T in the article?

~~~
psyq321
7T is the Nottingham University scanner. Cardiff is 3T Connectom A. These are
different sites / scans in the article.

In fact, 3T Connectom A is actually more optimized for Diffusion MRI / white
matter tract tracing compared to the available 7T scanners due to its enormous
300 mT/m gradient.

In theory, the best of both worlds would be a 7T+ scanner with ultra strong
gradient system such as the one developed by the HCP team, but such device
does not exist yet AFAIK.

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SemiTom
The sheer scale of connectivity of the human brain boggles. An interesting
read on neuromorphic computing's attempt to build systems informed by the
biological brain [https://semiengineering.com/neuromorphic-computing-
modeling-...](https://semiengineering.com/neuromorphic-computing-modeling-
brain/)

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criddell
Where is the neuron cell body? Would they be at the outside where the fibers
(axons?) seem to terminate?

I wouldn't have guessed that it would look so linear. I was expecting a much
more tangled appearance.

~~~
skndr
The tangled part is actually mostly 2mm thickness on the surface[0]. That's
why the folds matter so much:

[0] [https://28oa9i1t08037ue3m1l0i861-wpengine.netdna-
ssl.com/wp-...](https://28oa9i1t08037ue3m1l0i861-wpengine.netdna-ssl.com/wp-
content/uploads/2018/04/Self-Reflected-in-violets-1.jpg)

Check out this article for a pretty cool overview of the brain:
[https://waitbutwhy.com/2017/04/neuralink.html](https://waitbutwhy.com/2017/04/neuralink.html)

~~~
criddell
Thank you! Great links.

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JepZ
It's a tree ;-)

~~~
dredmorbius
Trees aren't brains.

Forests are brains.

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dubrocks
Funny, it looks about as complicated as I would have imagined it.

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odreem
The real challenge here is to understand the brain, and consciousness, without
putting it in computer terminology.

[https://aeon.co/essays/your-brain-does-not-process-
informati...](https://aeon.co/essays/your-brain-does-not-process-information-
and-it-is-not-a-computer)

~~~
JepZ
Sorry, but the author of that article clearly does not understand... It
doesn't matter if humans store data the way computers do, the point is, that
humans can be abstracted as state machines.

Yes, humans are certainly different than our PCs today, but that does not mean
that the principles are so different. E.g. humans seem to use a lot of lossy
'compression' while that is something we try to avoid in software in recent
years. So we use computers for the things humans cannot do very well and
therefore it appears that we are different.

I think the whole discussion about putting the human mind into computer
terminology is more about accepting that humans are just biological machines
versus believing that humans are special because they have a soul and are
different than any other animal.

~~~
goatlover
Alternatively, it's a seductive metaphor because humans love to try to explain
one thing in terms of another. Thus the universe is like a clock, and the laws
of physics operate like clockwork. Until QM and the metaphor broke down.

Similarly, the brain is like a computer. Until it's not.

Interesting how nobody runs it the other way. A computer is like the brain.
Why don't we? Probably because we understand computers a lot better than
brains, and use that analogy to make sense of something otherwise mysterious.

None of this has anything to do with a soul, btw. It's all a matter of how we
think about things.

The mistake is when we take our metaphors literally and try to make domain B
fit into domain A, despite obvious differences. Then we end up with a
convoluted view of B that's been distorted by being mapped onto A.

