The fMRI scans showed the higher a person’s math anxiety, the more anticipation of math activated the posterior insula, an inner brain region associated with registering direct threats to the body and experiencing pain. But interestingly, there was no pain response when the people were actually doing the problems.

This is not the first time scientists have noticed neural pain responses sparked by thinking about something. Previous researchers have noted physiological pain in response to social rejection, for instance. But there’s a strong evolutionary pressure for that–humans are social creatures–whereas math is a relatively recent invention.