Following on tests that have shown number-specific neurons, researchers at the University of Tübingen in Germany have now discovered fraction-specific neurons.
According to an article in NewScientist, researchers "scanned the brains of adults as they were shown a variety of different fractions - either as numerical ratios or in words. In both cases, specific groups of neurons altered their firing patterns. Crucially, control experiments showed that the volunteers weren't responding first to whole numbers, and then calculating the ratio, but were reacting to the fraction itself."
What this means for you and me is that all those years ago when we were struggling to learn fractions, it wasn't because we were idiots, it was because they weren't being taught in a way that took advantage of our fraction-comprehending brain bits. Phew!