Connectionists: how the brain works?

[Brian J Mingus]

The second episode of the new Cosmos provides an excellent example of how
evolution gets stuck in local minima that it can't climb out of.

- Brian
On Mar 19, 2014 6:00 PM, "james bower" <bower at uthscsa.edu> wrote:

> ah, someone once said (perhaps it was me) that arrogance and ignorance are
> a particularly dangerous combination in a scientist - not that there are
> not am absence of examples.
>
> In fact, Michael and I have both been accused of the former, I happen to
> know, but not generally of the later.
>
> :-)
>
> However, there is also something to be said for honesty and I am afraid to
> say that the opinion you express is more commonly held than I would like to
> think, certainly, it doesn't sit too far below the surface of many of the
> so called neuro-morphic models you see floating around, and I can tell you
> because I was there, that it was pretty apparent in the early days of the
> Neural Networks business as well.   Perhaps worth noting at the same time
> that some 'notables' in that effort, John Hopfield for example, didn't
> share that point of view, neither as far as I can tell did Carver Mead or
> Richard Feynman for that matter.  Collectively the course they taught at
> Caltech  in the early 80s on how the heck to figure out the brain was
> responsible for Caltech deciding to start the first computational biology
> graduate program (the CNS program).  Those guys were smart enough or knew
> enough, or both, not to dismiss structures evolved over millions of years,
> under harsh and unforgiving circumstances that did remarkable things.
>
> My advice is that nobody else should either.
>
> Jim Bower
>
>
>
> On Mar 19, 2014, at 6:13 PM, Brian J Mingus <brian.mingus at Colorado.EDU>
> wrote:
>
> The hippocampus and cerebellum might be necessary variance. Data from
> strokes and lesion studies suggest that they are not fully necessary,
> however. Also, they might be local minima in the design space, and we might
> be able to replace them with something simpler before we figure out exactly
> how they work, by first identifying what it is that they do and then
> inventing something better.
>
> Brian
>
>
> On Wed, Mar 19, 2014 at 2:27 PM, Michael Arbib <arbib at usc.edu> wrote:
>
>>  Ignoring the gross differences in circuitry between hippocampus and
>> cerebellum, etc., is not erring on the side of simplicity, it is erring,
>> period. Have you actually looked at a Cajal/Sxentagothai-style drawing of
>> their circuitry?
>>
>>
>> At 01:07 PM 3/19/2014, Brian J Mingus wrote:
>>
>> Hi Jim,
>>
>> Focusing too much on the details is risky in and of itself. Optimal
>> compression requires a balance, and we can't compute what that balance is
>> (all models are wrong). One thing we can say for sure is that we should err
>> on the side of simplicity, and adding detail to theories before simpler
>> explanations have failed is not Ockham's heuristic. That said it's still in
>> the space of a Big Data fuzzy science approach, where we throw as much data
>> from as many levels of analysis as we can come up with into a big pot and
>> then construct a theory. The thing to keep in mind is that when we start
>> pruning this model most of the details are going to disappear, because
>> almost all of them are irrelevant. Indeed, the size of the description that
>> includes all the details is almost infinite, whereas the length of the
>> description that explains almost all the variance is extremely short,
>> especially in comparison. This is why Ockham's razor is a good heuristic.
>> It helps prevent us from wasting time on unnecessary details by suggesting
>> that we only inquire as to the details once our existing simpler theory has
>> failed to work.
>>
>> > On 3/14/14 3:40 PM, Michael Arbib wrote:
>>  >> At 11:17 AM 3/14/2014, Juyang Weng wrote:
>> >>> The brain uses a single architecture to do all brain functions we are
>> aware of!  It uses the same architecture to do vision, audition, motor,
>> reasoning, decision making, motivation (including pain avoidance and
>> pleasure seeking, novelty seeking, higher emotion, etc.).
>> >>
>> >> Gosh -- and I thought cerebral cortex, hippocampus and cerebellum were
>> very different from each other.
>>
>>
>
>
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