Table 1.

Demographic characteristics of the samples

	Professional musicians (n = 20)	Amateur musicians (n = 20)	Non-musicians (n = 40)
Age (year)	23.05 (3.83)	25.95 (5.61)	26.92 (4.90)
Verbal IQ	119.23 (7.06)	122.57 (2.57)	118.18 (5.08)
Age of commencement (year)	6.00 (1.81)	7.65 (4.17)
Average practice time per day (hr)	2.23 (0.91)*	1.15 (1.0)*
Average practice time per day × duration of practice (hr × year)	39.1 (21.24)*	17.88 (9.74)*

Data are mean (SD).

^*p < 0.001.