[ExI] Brain emulation, regions and AGI [WAS Re: Kelly's future]

[Richard Loosemore]

Kelly Anderson wrote:
> On Mon, May 30, 2011 at 2:35 PM, Richard Loosemore <rpwl at lightlink.com> wrote:
>> Kelly Anderson wrote:

> Are there not different types of neurons in different areas of the
> brain? Would this not contribute to different algorithms being
> applied?

There are differences, yes, but in the cortex the main differences that 
I know about are all within-column (the layers of a column contain 
different types).  I stand ready to be corrected here, if someone knows 
about particular differences across columns.  The more obvious 
situations where unusual neurons compute different functions would be 
cases like the cerebellum, which appears to be a fine-motor-control 
mechanism (its the one that comes into play when a pianist learns how to 
generate complex patterns of finger movement without having to think 
about the exact details) .... in this case there are some very 
specialized types of cells (e.g. Purkinje) and architecture, all of 
which appears dedicated to the one function.

>>  Now, with that combination of input
>> ports and superhighways, the concepts that tend to be learned by the sea of
>> cortical columns tend to be specialized for the same reason that the shops
>> and businesses in a city tend to be specialized and localized .... because
>> the wholesale vegetable market is located *here*, the cattle market *there*
>> and the coffee houses *there* (so all the stock brokers arise in the coffee
>> houses!), .. and so on.
> 
> It would be fascinating to understand how these neighborhoods get set
> up. How much is genetic, how much experimental... probably a mix of
> both, I would suspect.

Indeed.  We have a bunch of information about the adaptability of the 
system:  if the left language area is damaged in early childhood, the 
corresponding right area takes over, and language develops normally. 
Later damage does not allow such a transfer to happen.  That single 
fact, as far as I am concerned, is a strong indication that the cortex 
is fairly homogeneous in its functioning, but only specialized as a 
result of the traffic that collects in the various places.

>> For example, I
>> think we may have the functional model of a cortical column in the next five
>> years, as a result of purely psychological analysis. That is, we could know
>> pretty much what the columns are doing, without having to ask the
>> neuroscientists what the circuitry looks like.  From the point of view of
>> AGI, that would make us able to build a human-like AGI soon after, while the
>> neuroscientists are still trying to figure out where to store the pictures
>> of the trillions of brain slices they are collecting (never mind how to
>> analyze those pictures).
> 
> Aren't there fully functional computational models of parts of the
> brain now? Aren't those models based on bottom up analysis, rather
> than top down?

There is a model of the cerebellum, but that really is a separate, 
fairly simple function.

If you are talking about the wiring diagrams that have recently been 
announced, I believe you will find that all those announcements are kind 
of sneaky:  what they actually mean by building a computational model is 
that they have *sampled* the neurons and patterns of wiring in a small 
area, and then done a *statistically* accurate reconstruction of that 
area.  I consider that to be a cheat.

I am less sure whether anyone has done a real circuit diagram or model. 
  Because all these announcements and press releases tend to be fuzzy on 
the details, it can be very frustrating to try to find out exactly what 
level of detail they claim to have done.  To the best of my knowledge, 
ALL of the current claims about having bottom-up models of parts of the 
brain are "cheats" in the above sense.


> The only reason I'm on the Whole Brain Emulation bandwagon is that the
> brain is the only example of intelligence we have. I get the whole
> bird/plane analogy, but without understanding the rules of avionics,
> you can't build a plane, and studying birds is ONE WAY of
> understanding avionics. Granted, this isn't the only way.

The bird-plane analogy is, alas, wholly false.  It would be valid if the 
system we were trying to duplicate were not a complex system.

So, the main implication of my 2007 complex systems paper was that it is 
extremely risky to assume that the plane (so to speak) can actually be 
built in any way other than by making it as close to a bird as possible.



Richard Loosemore