A cheerful English voice, crisp and elegant, asked her the question again. "How many coins do you
have there, Signora?"
Signora Gaddi stared at the coins in her hand for a long time, and then looked up to smile
apologetically at the doctor. It was a soft smile, warm, but tenuous and sad. The corners of her lips
trembled delicately when she tried to explain the inexplicable: she knew that there were more than
four, but she could not imagine how many. Were there eight? Or ten? Or some other strange
number, whose name hung heavily on her tongue and could not be uttered?
"It's all right, Signora. There are six coins." The doctor's voice was kind; he understood. He knew
of other people like Signora Gaddi, people who had little or no sense of numbers. These people
were not simply bad at math, nor were they poorly educated. The clinical terms are acalculia, for
people like Signora Gaddi who lost her sense of numbers after a stroke, and dyscalculia for people
who were born without numbers. But clinical terms don't go very far towards describing the people
who lead lives almost completely devoid of numbers.
S. Gaddi is a charming, middle-aged Italian woman. Before her stroke, she managed the books at
her family's hotel, and led a life filled with numbers. Room assignments, charges, debits, profits,
expenses - S. Gaddi was more than proficient at rapidly and accurately performing arithmetical
calculations. But since the day that a small blood vessel in her left parietal lobe burst, S. Gaddi has
been blind to numbers greater than four. She can readily perform addition and subtraction, she can
list number names in sequence - so long as all the digits involved are less than or equal to four.
Dr. Brian Butterworth, the University College London neuroscientist who worked with S. Gaddi,
"Since her stroke, [S. Gaddi's] life had been one of frustration and embarrassment.
She was unable to do things that previously had been second nature to her. She
could not give the right money in shops; she had no idea how much she was
spending or how much change she was getting. She could not use the phone.
There was no way to call her friends. She was unable to tell the time, or catch the
right bus." [more]
Interview by Ashish Ranpura