“ When the monkeys thought of numbers, Nieder saw that certain neurons became very active. On closer analysis, he made a fascinating discovery: the number-sensitive neurons reacted with varying charges depending on the number that the monkey was thinking of at the time. Furthermore, when a monkey was thinking “four”, the neurons that preferred four were the most active, of course – but the neurons that preferred three and the neurons that preferred five were also active, though less so, because its brain was also thinking of the numbers surrounding four. “It is a noisy sense of number,” explained Nieder. “The monkeys can only represent cardinalities in an approximate way.” It is almost certain that the same thing happens in human brains. Which raises an interesting question: if our brains can represent numbers only approximately, then how were we able to “invent” numbers in the first place?
