
Cracking the Brain’s Codes - fortepianissimo
http://www.technologyreview.com/featuredstory/528131/cracking-the-brains-codes/
======
sj4nz
There is probably not going to be any singular common code for all brains,
this is pattern recognition in a fatty sponge that grew from a single cell.
There will be families of similar neural networks in roughly the same
locations according to where the input/outputs are. My best intuition is for
some people who have "savant"-like powers are they were fortunate to grow
exceptionally useful networks for their needs.

If you're a bio-hacker with a penchant for hardware upgrades, I think that you
don't need to wait for anyone to discover "the encoding" to install an
interface to your mind. Just do it, and like everything else in your brain,
you'll spend a few weeks training your mind to use the new sense and digital
motor skills. Bio-feedback technology is already here.

~~~
negativity
I pretty much agree with this sentiment. They point out that information seems
to directly correlate with synaptic structures, so if that's true then it's
pretty doubtful that we'd be able to come up with a codified syntax for the
definition of memories, and then readily implement the syntax upon a living
creatire in a healthy (and cost-effective/legal) way, at least insofar as
directly enforcing synaptic structures known to provoke the recall of
memories.

Meanwhile, preparing experiments for creatures not yet alive is an altogether
different game. Growing a structure, by controlling chemical pathways, or
physically restricting the movement of neurons trained or genetically modified
to fire according to pre-defined external stimuli seems to be what the article
is driving at. But what good will that do me, if I'm already alive? Maybe a
tiny lobotomy for me, and then drop in a blob vat grown cells, that brain slug
their way into place? Would I still be me after that?

~~~
sj4nz
That would be a pretty macabre experiment. But I would guess that you would
still be you, but with the after effects of a stroke. The larger the volume of
the cut, the larger the damage. That would be the a form of brain transfusion
---an installation of living blank media. I am unsure of how you would
mentally direct the brain to use the new resource.

~~~
negativity
Well, ideally, the "new resource" is also genetically matched living brain,
and given the plasticity of brain tissue, and maybe by way of a novel as-yet-
uninvented means of coaxing, the two would mutually recognize the severed gap
between the two pieces, and heal back together. I mean I'm not a brain
surgeon, so I'm operating with possibly a great deal of very wrong assumptions
about how the brain recovers and heals from lacerations.

Would it be like trying to mend a spinal cord injury, which we still haven't
quite mastered? Or since it would be surgery, would the brain take to it like
rejoined pieces of healthy brain tissue, after the removal of a malignant
tumor? I suppose a lot of that would depend on the quality of the custom grown
tissue, and the technique of the operation.

Either way, nerve cells are essentially highly specialized finicky amoeba,
with dendrites acting as elaborately decorated pseudopods. They don't quite
"swim" like white blood cells, but sort of creep along, and test each other
out, delicately and selectively. And apparantly human cells can specialize to
the point where a single cell can recognize key concepts of individualized
external human identities (the article mentions Jennifer Aniston and Luke
Skywalker).

So, in the sense that dendrites are pseudopods, and pseudopods are, along
their external surface, celluar membranes (lipid bi-layers, decorated with
embedded proteins), the proteins are the specialized structures that
ultimately drive the behavior of the cell to direct it's psuedopods this way
or that way. It's a mixture of chemical reactions all the way down, even if
there is a layer of very fundamental electrical processes mixed in, due to the
deliberately maintained PH value, and shifting electrolytic potential of the
chemicals involved.

There was an article describing brain behavior as analogous to a swarm of
ants. This makes sense, since ant communities guide their collective behavior
by tagging their territories with scent, which gets reinforced with increased
ants marching along pathways. So, at the end of the day, some kind of
transplant process would probably require an arm of research tackling the
micro-scale and nano-scale structures and living behavior of the tissue, but
also the chemical aspects of how neurons sniff each other out, and decide to
stimulate each other through the electric polarity fluctuations of their
electrolyte juices.

------
collyw
Starts with the assumption that brain / brain activity = conscious self.

I am not aware of any evidence that this is the case. (That is not to say that
I think the two are unrelated, I just think this assumption ought to be
challenged, rather than taken for granted).

~~~
macspoofing
>Starts with the assumption that brain / brain activity = conscious self.

It's not assumption that there is nothing more to the mind than the material
brain. This is based on very strong empirical evidence.

We have about 100 years worth of Neuroscience.

We also have fundamental physics and laws of chemistry. There is no reason or
evidence to believe that something magical is happening in the brain, or that
somehow particles which behave according to the laws of physics outside of the
brain, somehow don't, when part of the brain. We have a very good
understanding of all the fundamental forces that govern the physics of our
everyday experience.

> I just think this assumption ought to be challenged, rather than taken for
> granted

Challenge it then. What is your reason to believe the laws of physics are
broken in the brain or that the mind is more than the material brain? Is there
even one shred of evidence for that?

~~~
aethertap
I would just add that the mind probably is partially an outgrowth of the
entire connected body system rather than just the brain in isolation. The
feedbacks between the hormonal system, parasympathetic/sympathetic nervous
system, and various other influences in the body have definite effects on the
function of the mind, assuming that mind encompasses behavior.

There's a fascinating course on this topic available from The Great Courses:

[http://www.thegreatcourses.com/tgc/courses/course_detail.asp...](http://www.thegreatcourses.com/tgc/courses/course_detail.aspx?cid=1597)

~~~
macspoofing
That's an interesting theory. I could see how that could, in principle, be
true. There's no reason why the neurons that make up our nervous system
wouldn't play a part in creating the mind.

~~~
aethertap
This came up today and reminded me of this thread so I thought I'd post it
here:
[https://news.ycombinator.com/item?id=7957057](https://news.ycombinator.com/item?id=7957057)

------
closetnerd
If you wan't a good intuitive understanding of the neocortex then I seriously
suggest reading up on Sparse Distributed Representations. A theory refined by
Gerard Rinkus and Jeff Hawkins.

~~~
sj4nz
Is this akin to Kurzweil's [Pattern Recognition Theory of Mind][0] that
estimates about 300 million pattern recognizers in the brain?

[0]:
[https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_R...](https://en.wikipedia.org/wiki/How_to_Create_a_Mind#Pattern_Recognition_Theory_of_Mind)

~~~
closetnerd
Honestly, for me at least, the ideas that Kurzweil puts forwards are
repetitive of the same things Hawkins discusses in his book [On
Intelligence][0]. Sparse Distributed Representations are a newer idea that
Kurzweil hasn't yet discussed. Actually there was a Google Talk that Hawkins
gave about Sparse Distributed Representations and Kurzweil was present.

[0]:
[http://en.wikipedia.org/wiki/On_Intelligence](http://en.wikipedia.org/wiki/On_Intelligence)

~~~
sj4nz
For anyone else following along there is the [Sparse Distributed
Representations][0] write-up at Numenta's GitHub.

[0]: [https://github.com/numenta/nupic/wiki/Sparse-Distributed-
Rep...](https://github.com/numenta/nupic/wiki/Sparse-Distributed-
Representations)

------
tokenadult
I liked this article after reading it. Before I read it, I thought it would be
yet another _Technology Review_ article by a staff writer, a superficial look
at unreplicated research, but I find as I reach the end of the article that
the two co-authors are both leading researchers on the topic and the second
co-author is Gary Marcus, a psychology professor who is a diligent author of
popular books about psychology to explain the latest findings from
neuroscience-based psychology to the public. This is worth a read. It's not
the last word on the subject, as the title alone should make clear, but it's a
good introduction to the current research program and the complications it is
discovering as scientists seek to develop a deeper understanding of the
function of the human brain.

------
ivan_ah
> _What matters most is not precisely when a particular neuron spikes but how
> often it does; the rate of firing is the main currency._

I'm not too sure about that.

My gut feeling is that at least half of the information in the brain is
encoded in the exact timing of the spikes. In a model that takes time into
account, certain neurons function as a "coincidence detector" sensitive to
certain events.

e.g. your brain deduces which direction a sound is coming from by analyzing
the delay difference for the sound input from each ear to arrive to the brain.
Specifically, sound-orientation detector neurons read from neurons of
different lengths to each ear. You know the sound is coming from front-and-
left if the coincidence-detector neuron that has a short lead to the left ear
and a long lead to the right ear fires.

~~~
joeyo
There are clear examples where spike timing matters a great deal and the
Jeffres model of sound localization, as you point out, is a great example of
this. However, spike timing codes seem to be more prevalent in the periphery;
rate codes dominate in central structures, and in particular the cortex.

The receptors of sensory afferents faithfully report the timing of individual
events (of photons, pinpricks of the skin, etc) with single spikes. But after
a few synapses the pattern of spikes looks much more like a (noisy) rate code.
The origin of the noise, whether it even _is_ noise, how the temporal code is
transformed into a rate code, and many other questions along these lines are
active research topics.

All that aside, Koch is well aware that there is evidence for both rate and
temporal codes. As he wrote, "spikes mean different things in different
contexts."

