CHICAGO, Feb. 9 (UPI) -- Research with deaf people in Nicaragua suggests language plays an important role in the brain's ability to learn the concept of numbers, U.S. scientists say.
Researchers from the University of Chicago found that deaf people in that country who had not learned formal sign language do not have a complete understanding of numbers greater than three, a National Science Foundation release reported Monday.
Not having been taught numbers or number words through formal education and exposure to formal sign language, the people in the study had learned to communicate using self-developed gestures called "homesigns," the researchers said.
While the homesigners had gestures for number, those gestures were accurately used for only small numbers, numbers less than three, and not for large ones, Chicago psychologist Susan Goldin-Meadow found.
Deaf people who acquire conventional sign languages, on the other hand, learn the values of large numbers because they learn a counting routine early in childhood, just as children who acquire spoken languages do.
"It's not just the vocabulary words that matter, but understanding the relationships that underlie the words -- the fact that 'eight' is one more than 'seven' and one less than 'nine,'" Goldin-Meadow said. "Without having a set of number words to guide them, the deaf homesigners in the study failed to understand that numbers build on each other in value."