[extropy-chat] Question on computational power of brain

[Eugen Leitl]

On Thu, Mar 15, 2007 at 12:04:26AM +0100, Anders Sandberg wrote:

> Most of the energy cost comes from maintaining the membrane voltages
> rather than the neural signal themselves. So the efficiency is pretty low.

Christof Koch in "Biophysics of Computation" suggests as a possible Ph.D.
thesis "It would be interesting to 'poison' an entire brain with TTX to block sodium
action potentials, and to measure the associated energy metabolism in
absence of any spiking. Is it possible that the fraction of energy devoted
to homeostasis versus computation/communication is heavily skewed towards
the former while in our microprocessors it is towards the latter?"

The book is from 1999, so a lot has happened in ops/J since.
I don't see why with MRAM-derived (static) logic and asynchronous (clockless)
designs energy drain of nonactive elements wouldn't be exactly zero.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
______________________________________________________________
ICBM: 48.07100, 11.36820            http://www.ativel.com
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 191 bytes
Desc: Digital signature
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20070315/47cb98a7/attachment.bin>