The BBC is reporting on some psychological research that decomposes various aspects of "mathematical" abilities. In short, the researchers seem to have localized serial digital counting and analog numerosity using neural imaging technologies. The latter is found in many animals, including rats and pigeons, and gives you a gestalt sense of proportion and ratio. It is not a precise accurate count, though when the set of discrete objects is less than 10 most humans exhibit a small enough error range that it operationally produces the same results as counting in sequence. Counting digitally on the other hand, an abstraction of ticking off your fingers as you count up over integers, is a more precise artificial feature of our species. Unfortunately I can't give you details because though the BBC reports that PNAS has published the paper I can't find it on their site.

Readers interested in this topic should check out The Number Sense and The Math Gene (I prefer the former because it is a less disjointed narrative). Also, this short (7 pages) review/opinion paper, Arithmetic and the Brain, might be of interest.

Update: Kevin McGrew has more.