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What the brain's wiring looks like

bbc.com

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Re: What the brain's wiring looks like

#81

Post by Asooka »

dunk010 wrote: post #78
vilhelm_s wrote: post #53

Earlier quoted context omitted.

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.

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...

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.

Re: What the brain's wiring looks like

#82

Post by chridal »

dunk010 wrote: post #78
vilhelm_s wrote: post #53

Earlier quoted context omitted.

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.

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...

No need for being rude.

Re: What the brain's wiring looks like

#83

Post by psyq321 »

DrAwdeOccarim wrote: post #76
psyq321 wrote: post #70

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…

It says it's 7T in the article?

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.

Re: What the brain's wiring looks like

#84

Post by hello_spinoza »

louithethrid wrote: post #62
jnicholasp wrote: post #56

Earlier quoted context omitted.

> Because the brain is composed of physical matter Is consciousness?

Yes, the process that makes conciousness is also governed by physics.

Hmm. It may not be that clear cut. Many modern philosophers (and some physicists!) are playing with the idea that consciousness is primary [1]. This would mean we have everything inside out, or upside down perhaps. But the matter is way, way more interesting and complicated that your reduction would suggest :)

[1] https://en.wikipedia.org/wiki/Panpsychism#Contemporary

Re: What the brain's wiring looks like

#85

Post by louithethrid »

jnicholasp wrote: post #64
louithethrid wrote: post #62

Earlier quoted context omitted.

Yes, the process that makes conciousness is also governed by physics.

> the process that makes conciousness is also governed by physics. How do you know that this is true?

Whatever it is, it follows a deterministic ruleset, else there be madness. If it follows a deterministic ruleset, and we can observe it directly or indirectly, and write those rules down- theorize about those rules - we can allmost call it physics.

If the feeling of beeing a clock, winds up a spring in the clock that works a mechanism that feels like fear on beeing predictable (aka exploitable) - that does not make the clock less observable.

Re: What the brain's wiring looks like

#86

Post by josefx »

dunk010 wrote: post #79
chongli wrote: post #77

Earlier quoted context omitted.

only 160 megabytes Take a bunch of source code. Compile it, obfuscate it, compress it, and encrypt it with AES such that the result is a 160MB blob. Now see how long it takes to figure out what it does, given a computer that costs a lot of money just to load your program and a long time to give you a result. The upper bound on the complexity of DNA as it relates to the complete expression of an organism phenotype is…

Most developers think of the genome like a big load of source code, and if only we could work out where the if and for statements were we could read it. This is an extremely naive and overconfident point of view; the analogy between source code and genomes is very poor. The genome is coding for proteins (by way of RNA). Those proteins are subject to all of physics (think: electrostatics, hydrophobics, ....), whereas…

> whereas your code is an abstract entity designed to run on a rather simple analogue of a Turing machine.

I cannot adequately put the insane laugh required as response to that into text form. So I will only write this and be just as right: going by physics the brain of a mouse can be adequately approximated by a perfect sphere.

Re: What the brain's wiring looks like

#87

Post by dunk010 »

Asooka wrote: post #81
dunk010 wrote: post #78

Earlier quoted context omitted.

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...

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.

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.

Re: What the brain's wiring looks like

#88

Post by dunk010 »

josefx wrote: post #86
dunk010 wrote: post #79

Earlier quoted context omitted.

Most developers think of the genome like a big load of source code, and if only we could work out where the if and for statements were we could read it. This is an extremely naive and overconfident point of view; the analogy between source code and genomes is very poor. The genome is coding for proteins (by way of RNA). Those proteins are subject to all of physics (think: electrostatics, hydrophobics, ....), whereas…

> whereas your code is an abstract entity designed to run on a rather simple analogue of a Turing machine. I cannot adequately put the insane laugh required as response to that into text form. So I will only write this and be just as right: going by physics the brain of a mouse can be adequately approximated by a perfect sphere.

I guess we'll all have to just imagine you're right, then. Mwahahaha!

Re: What the brain's wiring looks like

#89

Post by wu-ikkyu »

tazjin wrote: post #69
jnicholasp wrote: post #64

Earlier quoted context omitted.

> the process that makes conciousness is also governed by physics. How do you know that this is true?

What's the alternative? Lets assume there is some sort of physical process involved that we don't understand or even know about (unlikely), it would still be part of the physics that govern our universe.

The alternative, according to the scientific method is: "We don't know"

Re: What the brain's wiring looks like

#90

Post by wu-ikkyu »

Alain-lf wrote: post #67
jnicholasp wrote: post #64

Earlier quoted context omitted.

> the process that makes conciousness is also governed by physics. How do you know that this is true?

Because, as far as we can tell, everything that is part of our universe is governed by physics. Our brains are part of this universe, and conciousness is dependent on our brains.

>everything that is part of our universe is governed by physics.

Roughly 68% of the observable universe cannot be explained by physics ("dark matter").

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