Table 1.

Demographic and descriptive data

Intervention group		Age	Grade	No. of training sessions	Training performance first two sessions	Training performance last two sessions	SPM pre	SPM post	SPM FU	TONI pre	TONI post	TONI FU
Active control group	Mean	8.83	3.63	19.40	59.10	58.80	15.33	16.20	16.59	20.87	22.50	24.81
	(SD)	(1.44)	(1.47)	(2.09)	(12.80)	(17.70)	(4.32)	(5.10)	(3.95)	(6.04)	(5.06)	(7.30)
N-back group	Mean	9.12	3.72	19.09	2.17	2.93	15.44	16.94	16.52	20.41	22.03	24.07
	(SD)	(1.52)	(1.55)	(2.28)	(0.85)	(0.84)	(5.15)	(4.75)	(5.27)	(6.51)	(7.16)	(7.79)

Large training gain (n-back)	Mean	9.00	3.75	19.19	2.04	3.30	14.06	17.19	15.67	18.50	21.56	24.67
	(SD)	(1.79)	(1.65)	(2.26)	(0.75)	(0.75)	(4.91)	(4.74)	(5.07)	(4.91)	(6.93)	(8.15)
Small training gain (n-back)	Mean	9.25	3.69	19.00	2.30	2.55	16.81	16.69	17.43	22.31	22.50	23.43
	(SD)	(1.24)	(1.49)	(2.37)	(0.95)	(0.78)	(5.17)	(4.91)	(5.52)	(7.45)	(7.57)	(7.64)

Note: n = 62 (experimental group: n = 32, 14 girls; large training gain: n = 16, 7 girls; small training gain: n = 16; 7 girls; active control group: n = 30, 15 girls). There were no significant group differences on any of the pretest measures or the demographic variables. Training performance in the experimental group is given as mean n-back level; training performance in the active control group is given as percent correct responses. FU, follow-up test.