After "reading", now its time for Math.Carl Zimmer writes about the on-going research on our "Math Instinct":
"Despite the late appearance of higher mathematics, there is growing evidence that numbers are not really a recent invention—not even remotely. Cantlon and others are showing that our species seems to have an innate skill for math, a skill that may have been shared by our ancestors going back least 30 million years.
One sign that this skill truly is innate: Children enter the world with a head for numbers. Veronique Izard, a cognitive psychologist at Harvard University , demonstrated this in a recent study of newborns. She and her colleagues played cooing sounds to babies, with varying numbers of sounds in each trial. The babies were then shown a set of shapes on a computer screen, and the scientists measured how long the babies gazed at it. (The length of time a baby spends looking at an object reflects its interest.) Newborns consistently looked longer at the screen when the number of shapes matched the number of sounds they had just heard. For example, a baby who heard “tuuu, tuuu, tuuu, tuuu” would look the longest at four shapes, less at eight, and still less at twelve. Izard’s study suggests that newborns already have a basic understanding of numbers. Moreover, their concept of numbers is abstract; they can transfer it across the senses from sounds to pictures.
People do fairly well on these tests, which summons up a weird feeling in them: They know they are right, but they don’t know how they got the answer. Even in toddlers who cannot yet count, these studies reveal, the brain automatically processes numbers. From infancy to old age, mathematical intuition consistently follows two rules. One is that people score better when the numbers are small than when they are large. The other is that people score better when the ratio of the bigger number to the smaller one is greater. In other words, people are more likely to correctly tell 2 from 4 than they are to tell 6 from 8, even though both pairs of numbers differ by two. As we get older, our intuition becomes more precise. Other experiments have shown that a six-month-old baby can reliably distinguish between numbers that differ by as little as a factor of two (like 4 and 8). By nine months the ratio has dropped to 1.5 (8 and 12, for example). And by adulthood the ratio is just 10 to 15 percent. The fact that the same two rules always hold true suggests that we use the same mental algorithm throughout our lives
Brain scans using magnetic resonance imaging (MRI) and positron emission tomography (PET) are shedding some light on how our brains carry out that algorithm. Neuroscientists have found that when people do mathematical intuition problems, a strip of neurons near the top of the brain, surrounding a fold called the intraparietal sulcus, consistently becomes active. And when we confront more difficult problems—when the numbers are bigger or closer together—this region becomes more active.
Brain scans using magnetic resonance imaging (MRI) and positron emission tomography (PET) are shedding some light on how our brains carry out that algorithm. Neuroscientists have found that when people do mathematical intuition problems, a strip of neurons near the top of the brain, surrounding a fold called the intraparietal sulcus, consistently becomes active. And when we confront more difficult problems—when the numbers are bigger or closer together—this region becomes more active.
The monkeys were able to learn to release the lever for matching numbers and to keep it down for numbers that did not match. If they had succeeded simply by matching shapes, you would expect them to sometimes confuse similar-looking numbers: They might choose 1 as a match with 4 because both are made of straight lines, for example. But Diester and Nieder found that the monkeys got confused in a different way. The monkeys were most likely to mix up numbers that were numerically close to each other: the sticklike 1 and the curvaceous 2, for example. What’s more, the monkeys took more time to release the lever if larger numbers matched than if smaller ones did—another sign that the animals were responding to quantity, not shape.
If mathematics ability is innate why isn't that everyone is at least above average in it (even after creation of rehearsal-loop by tutoring maths during childhood) or worse, some even despise it? Does that mean some of us have an under-developed "symbolic" brain? or its just that Dorsolateral prefrontal cortex is used for a different purpose (recycled) in them?
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