Fig. 4.

Discrimination performance (d’) presented as a function of the type of strategies used in the contour conditions (visual and auditory), and separately for musicians and non-musicians. C Contour, PC possibly involving contour, N none. Above each box, the number of participants that reported using that strategy. Inside each box, the horizontal line indicates the median. The red diamond represents the mean. The edges of the box represent the first quartile (Q1) and the third quartile (Q3) (i.e., the 25th and the 75th percentiles). The interquartile (IQR) range is the height of the box (i.e., Q3–Q1). The upper whisker extends from Q3 to the largest value, no further than 1.5 * IQR from Q3. The lower whisker extends from Q1 to the smallest value no further than 1.5 * IQR from Q1. The black dots represent the data points inferior or superior to these cut-off values