ABSTRACT
This chapter summarizes the evidence that almost all humans and many other animals have a basic understanding of number. It considers how numbers are represented in the brain; where number meaning is represented in the brain; and the extent to which numerical cognition depends upon other cognitive systems. Experimental studies involving judgments of the size of collections typically use arrays of dots and can be broadly divided into two domains: those that require an exact assessment of number versus those that require a relative, or approximate, assessment of number. The same region of the brain is activated by numbers across different cultures and writing systems. Nonsymbolic processing of numbers show striking similarities across species and, in humans, processing of number symbols show comparable effects. Single-cell recordings from the parietal and frontal lobes of macaques suggest a likely neural substrate for this effect: namely, neurons that respond to some numbers more than others, but with a general tendency for larger numbers to be linked to less specificity in terms of the neural response.
