That Thinking Feeling

Finger-counting and synaesthesia

There is a small group of people (number-space synaesthetes) who think of numbers as having positions in space, but different people’s layouts look quite different. It seemed reasonable that the direction you count on your fingers (starting on the left or on the right) might be linked to how your number-space synaesthesia looks. Jamie Ward kindly lent me his filing cabinet of questionnaires recording synaesthetes’ number-space layouts, and then I contacted those synaesthetes to ask about how they counted to 10 on their fingers. Surprisingly, finger-counting direction and number-space synaesthesia layouts have no connection – so perhaps synaesthetes don’t rely on their fingers when they’re learning to count, unlike almost everyone else. This could have effects on how synaesthetes do maths.

Jonas, C. N., & Ward, J. (2014). Number-space associations in synaesthesia are not influenced by finger-counting habits. Journal of Cognitive Psychology, 26(2), 232-240.