Re: What evidence is there that a neuron is digital computer ?

On Jul 26, 11:38 pm, c...@xxxxxxxx (Curt Welch) wrote:
I said the pulses have infinite temporal resolution.
...
I've said nothing about pulse encoding sensors in
this thread and what they can or can not do.

So what was the use of observing that there is an
infinite temporal resolution if you couldn't use it?

A point in space also has "infinite resolution" but
in practice there is a limit to how you can use it.
How do you set it and read it out?

What I had in the back of my mind was all your talk
in the past about how your pulse sorting units could
take two pulses in at "once" and would be able to
sort them according to arrival time as in time there
would be a difference in their arrival time no
matter how small. What is the hardware for this?


Can you see it might have a problem coding small
values in succession as it has to take time off
to recharge?


Sure. If it can't fire again for 10 ms then it
can't code for anything less than 10 ms. Isn't
that obvious?


I thought so but you were saying the neuron makes
use of higher resolutions in time.


It's not that it's just an infinite number of
values between 0 and 500 John, there's an infinite
number of values between 300 and 301.


But can you make use of the infinite values between
two points in space or time? I say there is a space
and time frame below which a particular piece of
hardware cannot discriminate between the values in
that frame.

All this is about claims you made to me with your
pulse sorting unit that it could always determine
which pulse arrived first because the chance of
them having the same value in the sea of infinite
values is as good as zero. What I couldn't figure
out is what hardware could do this if the pulses
were very close in time.


If you are to build a unit that has a "temporal
function" it has to be physical and I assume, at
this stage, it will be built out of your standard
electronic components.


Ok. I guess. But now you are totally changing
the subject so I don't get what's going on in
your mind.


That you have to implement things in a physical form
and that rules out using your infinite resolution.


It is unclear to me what you mean by "spatial function
computing neural networks". As far as I know the units
I play with are functionally just as "temporal" as
any real neuron.


Well then, lets start from scratch again.
...


After I posted I realised what you meant by spatial
function. My confusion was you implying I didn't talk
about dealing with temporal patterns but that is not
true. I suggested they were dealt with by being
converted to a spatial code which is what memory is
even if it is scattered through the whole net as
a volage charge on a capacitor or a digital value
in a counter.


What I've been talking about as temporal functions,
basically map to the idea of sequential logic. But
yet, there are subtle differences in how I normally
think about it because I think abstractly in terms
of processing real analog temporal pulse signals
instead of in terms of digital signals.


Yes and it this subtle difference in how you think about
it that has been the core problem when I try and imagine
how it could be implemented in real hardware.


The only neural networks you have talked about, have
no ability at all to solve that problem - and it's why
I have not yet been interested in the networks you have
talked about.


Not true. You just didn't like the idea of the temporal
pattern being converted to a spatial form. I assume it
is because you see limited resolution in this form then
the infinite possible number of positions in time that
a pulse may turn up at the unit.


< snip >


Does any of the above help you understand what I've been
talking about?


I have always believed I understood what you imagine about
infinite high resolution analog temporal coding with pulses
but what wasn't clear was the cold hard need to convert
this abstraction to an implementation in actual hardware
that could make use of it.


JC


.

Relevant Pages