Re: Brain size (was Save the Whales)

Dan Clemmensen (
Sat, 27 Sep 1997 21:59:30 -0400

Nicholas Bostrom wrote:
> The Low Golden Willow wrote:
> > A large brain may require a large body, but by what I've skimmed from
> > Churchland a large body might well need a large brain to function.
> > There's a distorted map of your skin on the surface of your brain. More
> > skin, more map.
> I have often heard this argument, but I think it is wrong. Processing
> of tactile information takes up only a small fraction the cortex.
> Therefore, if we double body area, or the number of tactile
> receptors, and if we assume that this requires that tactile sensory
> cortex also doubles, this will mean that the total brain size only
> goes up by a percent or so.
Furthermore, the square-cube "law" means that the available brain
mass goes up as the cube of the linear dimesnion while the skin area
goes up as the square.