Posted: December 24th, 2016

Rub your index fingers gently over a piece of very coarse sandpaper a few times and rate its coarseness on a scale from 1 (very soft) to 7 (very coarse).

Rub your index fingers gently over a piece of very coarse sandpaper a few times and rate its coarseness on a scale from 1 (very soft) to 7 (very coarse). After a minute or two, rub the same finger over the paper and again rate its coarseness. Did your perception of the coarseness change? How?