Table 2.

Performance on the WAIS-IV subtests, separately for musicians and non-musicians

WAIS-IV SUBTESTS	Musicians N = 24 (18 females)	Non-musicians N = 24 (19 females)	Group comparison
			p value	Cohen’s d
Digit span forward (WM)	11 (1.89)	11 (1.35)	p = 1	d = 0
Digit span backward (WM)	9.79 (2.17)	9.08 (1.56)	p = 0.53	d = 0.37
Digit span sequencing (WM)	9.87 (2.72)	9.79 (1.15)	p = 1	d = 0.04
Arithmetic (WM)	15.83 (2.93)	14.92 (3.52)	p = 0.53	d = 0.28
WM index (composite score)	106.7 (14.87)	102.3 (12.97)	p = 0.53	d = 0.32
Coding (PS)	91.58 (15.68)	78.83 (13.6)	p = 0.032	d = 0.87
Symbol search (PS)	41.29 (8.35)	41.08 (6.6)	p = 1	d = 0.03
PS index (composite score)	117.8 (15.73)	108.8 (14.18)	p = 0.164	d = 0.61

p values refer to the comparison between groups through t tests (FDR corrected). The last column represents the effect size expressed with the d of Cohen. The WM and PS indexes (composite scores) are computed based on the raw score of each subtest, which was converted into a scaled score taking into account the age of participants (based on normative data), and then transformed in the final standardized index with M = 100 and SD = 15.

WM working memory, PS processing speed