Once again, scientists are trying to read your mind. Specifically, they are using fMRI (functional magnetic resonance imaging) to see what areas of the brain people use to process numbers, and even to determine what number a person just viewed.
Test subjects were shown images with either an amount of something—in this case a bunch of dots—or a numeral like 2, 4, or 6. Scientists suspected that our brains use overlapping areas to process quantities and their symbolic representations, however the findings suggest that people process the fundamental idea of a quantity differently from the way they process a symbol representing that quantity [Science News]. When a test subject looked at two dots and later at the number 2, different areas of the brain were activated, researchers report in Current Biology.
Scientists already knew that the the frontal and parietal lobes of the brain are involved in number processing. Monitoring those areas, researchers saw distinct activity patterns associated with specific numerals and dot quantities, and used the info to determine what number the test subjects had just seen.
When it came to small numbers of dots, the researchers found that brain activity patterns changed gradually in a way that reflected the ordered nature of the numbers. For example, one might be able to conclude that the pattern for six is between that for five and seven. In the case of the numerals, the researchers could not detect this same gradual change. This suggests their methods simply might not be sensitive enough to detect this progression yet, or that these symbols are in fact coded as more precise, discrete entities in the brain [LiveScience].
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