Capacity of the brain

bj flanagan Wordsmyth at
Tue Aug 31 08:54:44 EST 1999

TTK Ciar wrote:

>   * Some low-level details of the neuron and synapse necessary for knowing
> the answer to the question are not currently known to medical science.

bj: I would say that this is undoubtedly true.

>   * The capabilities of an information system is not necessarily equivalent
> to the sum of its parts, or even necessarily readily ascertainable by the
> examination of its parts.

bj: Which assertion is dramatically true of quantum systems.

>   * What we think we do know about how neurons and synapses work is not
> readily comparable to how modern computer systems work, though it might be
> able to compare them strictly on the basis of informational complexity.

bj: My best guess is that information theory is inadequate to the
problem of modeling the varieties of sensory experience, much less the
higher-order cognitive processes.

>   It is *believed* that synapses convey data in binary format, ie they can
> fire or not fire, and the only information the neuron possesses about its
> neurons are that they are firing or not firing.

bj: I would predict that this widely held assumption will prove to be
grossly simplistic.

... the use of functions within the neuron more
> complex than the threshold function, and non-binary use of the signal
> generated by firing synapses (ie, as wave forms;

bj: I am firmly persuaded that we ought to look for wave forms riding
along on the "carrier waves" of synaptic discharges.

>   On the extreme end, Penrose (who is, in my opinion, completely off the wall)

bj: No. Penrose only made it respectable for us "quantum mind" guys to
talk about such things. Before he jumped on board, I was only a voice
whining in the wilderness.

has hypothesized that individual neurons are quantum computers of
> enormous power.  In my own opinion, it is reasonable to construct a
> hypothetical "low end" model of the neuron as the simple threshold device
> which is influenced by gradual changes in neurotransmitter levels not
> directly affected by neural computation, and a hypothetical "high end"
> model of the neuron as a simple arithmetic and/or logical function, with
> each firing synapse contributing up to 4 bits of information apiece via
> waveform variation.

bj: Whereas I would argue that this approach is highly unreasonable. But
I am in the middle of hay fever season, and chronically tired and
cranky, so I will put off arguing the matter for a while


Quanta & Consciousness

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