Ben Goertzel wrote:
It's pretty clear that humans don't run FOPC as a native code, but
that we can learn it as a trick.
I disagree. I think that Hebbian learning between cortical columns is
essentially equivalent to basic probabilistic term logic.
Lower-level common-sense inferencing of the Clyde-->elephant-->gray
type falls out of the representations and the associative operations.
I think it falls out of the logic of spike timing dependent long term
potentiation of bundles of synapses between
cortical columns...
The original suggestion was (IIANM) that humans don't run FOPC as a
native code <em>at the level of symbols and concepts</em> (i.e. the
concept-stuff that we humans can talk about because we have
introspective access at that level of our systems).
Now, if you are going to claim that spike-timing-dependent LTP between
columns is where some probabilistic term logic is happening ON SYMBOLS,
then what you have to do is buy into a story about where symbols are
represented and how. I am not clear about whether you are suggesting
that the symbols are represented at:
(1) the column level, or
(2) the neuron level, or
(3) the dendritic branch level, or
(4) the synapse level, or (perhaps)
(5) the spike-train level (i.e. spike trains encode symbol patterns).
If you think that the logical machinery is visible, can you say which of
these levels is the one where you see it?
As I see it, ALL of these choices have their problems. In other words,
if the machinery of logical reasoning is actually visible to you in the
naked hardware at any of these levels, I reckon that you must then
commit to some description of how symbols are implemented, and I think
all of them look like bad news.
THAT is why, each time the subject is mentioned, I pull a
sucking-on-lemons face and start bad-mouthing the neuroscientists. ;-)
I don't mind there being some logic-equivalent machinery down there, but
I think it would be strictly sub-cognitive, and not relevant to normal
human reasoning at all ...... and what I find frustrating is that (some
of) the people who talk about it seem to think that they only have to
find *something* in the neural hardware that can be mapped onto
*something* like symbol-manipulation/logical reasoning, and they think
they are half way home and dry, without stopping to consider the other
implications of the symbols being encoded at that hardware-dependent
level. I haven't seen any neuroscientists who talk that way show any
indication that they have a clue that there are even problems with it,
let alone that they have good answers to those problems.
In other words, I don't think I buy it.
Richard Loosemore.
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