As time goes by, bets against the veracity of the
Gallistel-King conjecture (see here
and here)
are becoming longer and longer. Don’t get me wrong. The cog-neuro world is not
about to give up on its love affair with connectionism. It’s just that as the
months pass, the problems with this (sadly, hyper Empiricist) view of things
becomes ever more evident and this readies people for a change. Moreover, as
you can’t beat something with nothing but a promise of something (you actually
need a concrete something), it is heartening to see that the idea of classical
computation within the neuron/cell is
becoming ever more conventional. Here
is a recent report that shows how far things have come.
It shows how living cells can classically compute, in the
sense of programmable circuits (“predictable and programmable RNA-RNA
interactions”), which “resemble” conventional electronic circuits” with the
added feature that they “self-assemble” within cells “sense incoming messages
and respond to them by producing a particular computational output.”
Furthermore, “these switches can be combined…to produce more complex logic
gates capable of evaluating and responding to multiple outputs, just like a
computer may take several variables and perform sequential operations like
addition and subtraction in order to reach a final result.” Recall, that as
Gallistel has long argued, being able to compute a number and store it and use
it for further computation is precisely the kind of neural computation we need
to be cognitively adequate. We now know that cells have the chemical
wherewithal to accomplish this using little RNA circuits, and that this is
actually quite easy for the cell to do (“The RNA-only approach to producing
cellular nanodevices is a significant advance, as earlier efforts required the
use of complex intermediaries, like proteins”) reliably.
So, the idea that cells can
classically compute is true. It would be surprising if evolution developed an
entirely novel computational procedure instead of exploiting the computational
potential of ready available ones to get our cognitive capacities off the
ground. This is possible (of course) but seems like a weird way to proceed if
the ingredients for a standard kind of computation (symbolic) are already there
for the taking. This is the point of the Gallistel-King conjecture, and to me,
it seems like a very good one.
