"Finding numbers in the brain" by C.R. Gallistel: https://royalsocietypublishing.org/doi/full/10.1098/rstb.201...
Edit: also see his article on this from 2015 "Here's Why Most Neuroscientists Are Wrong About the Brain" https://nautil.us/blog/heres-why-most-neuroscientists-are-wr...