🚀 go-pugleaf

In article <876391847snz@longley.demon.co.uk>,
David@longley.demon.co.uk (David Longley) wrote:

>In article <343d5a33.43513184@news.earthlink.net>
>           savainl@earthlink.net "Louis Savain" writes:
>
>> In article <876306121snz@longley.demon.co.uk>,
>> David@longley.demon.co.uk (David Longley) wrote:
>> 
>[...]
>> > But a  temporal  relation 
>> >alone  is not sufficient (as Kamin showed long ago). If one  goes 
>> >beyond  "delay",  to "trace" conditioning, it looks  like  higher 
>> >levels of processing such as the hippocampus is required - but as 
>> >I've said before, this is already getting into levels of learning 
>> >in the neuroaxis...
>> 
>>   I'm sorry, this is nonsense.  A signal is but message indicating
>> that something happened at a specific time.  The neuron processing the
>> signal has no idea what that something is and could not care less.  It
>> only gets the signal and that is it.  To make sense of anything it
>> needs to find several signals to determine their relationships, if
>> any.  Temporal relationship is the **only** type of relationship that
>> can exist between events (signals).  Period.  David, you are falling
>> headlong into intensional superstition here and your appeal to
>> obsolete authority makes it worst.
>
>*All* of classical conditioning is based on temporal order.  What 
>I'm  talking  about  above is  different  classical  conditioning 
>paradigms, ie relations between CS-UCS delivery. 

  David, in the quoted paragraph above you said that "temporal
relation alone is not sufficient" and that this was showed by Kamin.
I pointed out that temporal order is it and that there is nothing
else.  Now you seem to be backtracking on your original statement
without coming right out and say that you were mistaken.  Fine.

>> >What  I see here in these threads is some excitement on the  part 
>> >of  proponents  of  this work, but it seems  to  reflect  "their" 
>> >personal  discovery  of something which a large number  of  other 
>> >researchers have been working on in the context of small  systems 
>> >models  (Richard Thompson's group) for several decades now.  That 
>> >work  makes no claims to being able to build "learning  machines" 
>> >on the other hand, just unravel some of the neuromechanics behind 
>> >basic conditioning processes.
>> 
>>   The actual physiological mechanism responsible for temporal
>> processing is only now making it to the surface (see the above
>> reference).  All we had before that was behavioral studies in
>> classical conditioning.  Not much more.  I do agree however that
>> classical conditioning tells a powerful tale about biological learning
>> but we are pragmatic technologists and we need hard *mechanisms* to
>> work with not just observations of behavior.
>
>That's  not  true as I have said. Go back and  look  through  the 
>neuroscience literature. Look at the work on LTP, and  especially 
>look at Thompson's work.

  I am not saying I am an expert in neuroscience.  Of course everyone
involved in the field must have known or suspected that temporal order
was essential to the working of neurons, especially with regard to
dendritic computation.  I am saying that the dramatic effect of
temporal order on synaptic plasticity was not discovered until
recently by Dr. Henry Markram and his colleagues at the Weizmann
Institute of Science.  If I'm wrong, maybe you can point out specific
references where the effect reported by Markram was previously
published by others.
 
>> >To be a breakthrough, a discovery has to be more than one getting 
>> >excited   about   something  one  learns  -  to  be   a   genuine 
>> >breakthrough, one needs to know the literature and be working  in 
>> >the field to know what is and is not new and worthy of attention. 
>> >How else can one ascertain whether it is indeed a breakthrough?
>> 
>>   Sorry, you have no idea what you are talking about in the context of
>> recent work done in neuroscience.
>
>Having  spent  4  years in the Division  of  Neurophysiology  and 
>Neuropharmacology  working on the neural and neurochemical  basis 
>of learning as a postgrad I can assure you that I know  something 
>about neuroscience. 

  OK fine.  But how long ago was that?  The Markram discovery was
published only this year.

>> >If you want to make any real progress on "learning machines"  you 
>> >are  going  to  have  to come to grips with  the  issues  I  have 
>> >discussed elsewhere, 
>> 
>>   David, your fascination is with deduction and that has absolutely
>> nothing to do with learning.  So you could not possibly understand
>> anything worthwhile about the subject.  Learning is forcibly inductive
>> and this is the pure extensional truth whether you like it or not.
>
>You  have a preconception that this is the case. What  you  don't 
>appreciate  is  why  I  have  spent  so  much  time  and   effort 
>critcisiing these preconceptions. I was doing so long before  you 
>starting making your "announcements".

  You have ever showed that learning is not inductive and you never
will.  As I said, this is the pure extensional truth.

>But  as I say - let's see something other than - "I've read  this 
>article"  and "we have a breakthrough" (but haven't got  anything 
>to show for it yet - just a conviction).

  The breakthrough is not mine but that of Markram and his colleagues
and many others who are working hard to unravel the mysteries of
neural adaptation.  I am convinced that from now on, rapid progress
will be made computational neuroscience because of it.  Indeed, for
the first time in years, I can see the light at the end of the tunnel.
This is exciting.  I am sorry that you can't partake in the
excitement.

>Show me (and everyone else) that I'm wrong....

  At this point David, I'm afraid that showing you anything will not
do much good.  I suspect that if someone were to show you an inductive
learning machine, able to learn several languages and converse
fluently on various subjects, you would still claim that it is not
intelligent.  But no one would care about your definition of
intelligence.  The whole world except David Longley would be more than
convinced that the machine was indeed intelligent.

>[...]
>With  all  of the models of learning which have  been  programmed 
>since  the  late 60s (and the implications of  the  Church-Turing 
>Thesis), why do you think there aren't ANNs running machinery  or 
>missiles  all  over the place? - Might it not be  because  what's 
>required  are reliable, predicable machines - not ones which  are 
>at  the  mercy of local characteristics of the  environment.

  No.  It's because the methods used in ANNs up to now are either
wrong or biologically implausible.  That is why the field of
computational neuroscience was born, as a way for neuroscientist to
distance themselves from conventional ANNers and build more plausible
models.  With the newest discoveries (an inductive process BTW) in
neurophysiology, I anticipate rapid progress in the field.

>But go ahead - "build" your machine, and find out for yourself.

  You just be patient.  It won't be long now.  Not that our machine
will change your mind, mind you.

Regards,

Louis Savain

President, Marengo Media, Inc.