Perceptual recognition of the stimuli. The box plot shows the median (horizontal line at the center of each box), two central quartiles (25%) above and below the median in the shape of a box, and the first and last quartile (22.5%) graphed as extension lines (“whiskers”). The dots are observations outside the 95% confidence interval. Asterisks at the top of each column denote the confidence of the result, with a single asterisk indicating 5% error (⁠$p<0.05$⁠), a double asterisk indicating 1% error (⁠$p<0.01$⁠), a triple asterisk indicating 0.1% error (⁠$p<0.001$⁠), and the abbreviation n.s. indicating “not significant.”