Fig 4. Frequency of scraping events directed towards the left or the right cheek.

Bar-graphs showing the frequency of the scraping events (SCRA) that each subject directed specifically towards the left side of their face (see S1 Fig) across the four different conditions when the colored mark was placed on the left cheek (a) (CM, OM, SHAM, MARK 1; df = 3; Julia: χ² = 86.02, p < 0.0001; Calippo: nd—expected values less than 5; Gina: χ² = 32.52, p < 0.0001; Betsie: nd—expected values less than 5) and when it was placed on the right cheek (b) (CM, OM, SHAM, MARK 2; df = 3; Julia, Calippo, Gina, Betsie: nd—expected values less than 5).