In "What Counts: How Every Brain Is Hardwired for Math",
cognitive psychologist Brian Butterworth argues that we are born with
brain circuits specialized for answering the question "How many?" While
all of us possess this Number Module, as he refers to it, Butterworth
deftly slips in the question of whether a collection of experimentally
confirmed number-crunching chimpanzees, ravens and at least one parrot
possess a "predecessor" of our Number Module. Nor do we know if these
savant-like animals use the same brain areas to carry out their numerical
tasks.
We do know that adults with brain damage can lose
the ability to perform numerical operations that would provide little
challenge to the average primary grader. As examples Butterworth
introduces us to a cast of fascinating patients including: Signora Gaddi,
who despite otherwise normal cognition cannot count above the number four;
Mr. Bell, whose understanding of speech or written language is almost
nonexistent but who nevertheless retains a serviceable ability in
arithmetic; Mr. Morris, who after hearing a series of numbers cannot
repeat back more than two of them yet can carry out accurate mental
calculations involving two three-digit numbers. On the basis of these
examples Butterworth concludes that "arithmetical facts and arithmetical
procedures occupy different circuits in the brain." Even more intriguing,
"writing words and writing numerals,reading words and reading numbers all
involve distinct brain circuits, despite having common input pathways from
the eyes and common output pathways to the hands."
Given this emphasis on the brain as an
explanation for mathematical abilities, Butterworth's conclusion that
"anybody can be a math prodigy" comes as asurprise. To support this
contention, he refers to a famous study by the French psychologist Alfred
Binet showing that experienced cashiers at the Bon Marche department store
in Paris could calculate more rapidly than two math prodigies competing
against them. Butterworth favors the explanation that "in those days a
cashier was recognized as highly skilled" rather than the more reasonable
one that "self-selection played a part: those who couldn't do [math] or
didn't enjoy doing it moved on to other positions within the store." At
another point, using the English shorthand for "mathematics," he concedes
what we mathophobics have always known: "Having good natural abilities for
maths may be exactly the reason for choosing maths in the first
place."