[nengo-user] 9 mm^2 cortex regions

[Alex Miller]

Hello, everyone:

I'm reading How to Build a Brain, and I guess I'm missing the big picture.

Section 4.3 seems to argue that a 9 mm^2 cortex region must be able to
bind and unbind 500D semantic pointers, which refer to lists of up to
8 pairs of concepts from about 60,000 that humans have in their
vocabulary.

Judging by its size, the cortex must contain 150,000 such regions. Is
the idea that each of them operates on semantic pointers of the same
kind? Why does, say, V2 need to be able to work with representations
created by the auditory cortex, or with higher-level concepts like
"science" (one of those 60,000)? And if it doesn't, why does it need
to be 500D?