Folha: “The Meaning of Numbers in Infants”
Reprint of Marcelo Viana’s column in Folha de S. Paulo
I mentioned here last week that recent experiments suggest that a sense of numbers may be innate in our species: from a very early age, we extract numerical information from our sensory impressions without even thinking about it, just as naturally as we perceive the colors of the objects we see.
That being the case, what are the intrinsic mechanisms of our brain that underlie our perception of numbers, regardless of language and culture? To try to answer this question, researchers at the University of Trento in Italy analyzed the brain activity of a group of 21 infants, up to three days old, when exposed to different numerical stimuli.
Experiments with such young infants are difficult, of course, primarily because they sleep all the time, and their periods of wakefulness are very short. Each infant was fitted with a small cap containing sensors that allow researchers to monitor electrical impulses in the brain. During the periods when each baby was awake, with their eyes open, the researchers played audio clips repeating the same sound (for example, “la”) 4 or 12 times and, at the same time, showed images containing 4 or 12 dots.
Electrical monitoring showed that activity in the region of the brain that perceives and organizes sensory information was lower when the number of sounds matched the number of dots and increased when the numbers of sounds and dots differed. It was as if the baby became more alert when there was a discrepancy between the two types of information—auditory and visual—and relaxed in the other cases.
This type of behavior is well known in adults: when exposed to repetitive stimuli, our brain reduces its activity, as if it were attaching less importance to the information. This is an adaptive advantage that allows our brain to function more efficiently, freeing up cognitive resources for situations in which the conditions around us change.
One particularly intriguing aspect of research on the development of number sense in young children concerns what this development tells us about the child’s future relationship with mathematics. Another group of researchers, from the University of Padua, analyzed the stage of development of numerical sense in 60 one-year-olds and compared it with the mastery of basic mathematical concepts by 40 of those same children three years later.
The study’s main finding was that there is a strong correlation between these two points in time: “Understanding numbers at 12 months is a good predictor of mathematical ability at age 4, even when we account for factors such as inhibition, general intelligence, and perceptual abilities.”