. 2014 May 16;5:443. doi: 10.3389/fpsyg.2014.00443

Table 2.

Hierarchical regression models predicting children's performance on verbal and visuospatial working memory (WM) spans.

	Verbal WM			Visual WM
	B	SE	β	B	SE	β
STEP 1
Intercept	0.03	0.33	–	0.15	0.29	–
Age	0.02	0.01	0.45^***	0.02	0.00	0.43^***
R²(ΔF)	0.21 (15.31^***)			0.19 (13.50^***)
STEP 2
Intercept	−0.004	0.33		0.15	0.30
Age	0.02	0.01	0.32^***	0.02	0.00	0.43^***
Gender	0.17	0.12	0.16	−0.01	0.11	−0.01
R²(ΔF)	0.23(1.96)				0.19 (0.01)
STEP 3
Intercept	−0.26	0.34	–	−0.02	0.31	–
Age	0.02	0.01	0.32^*	0.01	0.01	0.34^*
Gender	0.20	0.12	0.19	0.01	0.11	0.01
Nonvb. Intelligence	0.04	0.02	0.28^*	0.03	0.02	0.22
R²(ΔF)	0.30 (5.32^*)			0.23 (2.91)
STEP 4
Intercept	0.32	0.38	–	0.38	0.36	–
Age	0.01	0.01	0.24^*	0.01	0.01	0.28^*
Gender	0.21	0.11	0.19	0.01	0.10	0.01
Nonvb. Intelligence	0.03	0.02	0.25	0.02	0.01	0.20
Anxiety	−0.01	0.00	−0.31^**	−0.01	0.00	−0.25^*
R²(ΔF)	0.39 (8.08^**)			0.28 (4.44^*)
STEP 5
Intercept	−0.83	0.40	–	0.15	0.35	–
Age	0.01	0.00	0.16	0.00	0.01	0.11
Gender	0.17	0.09	0.16	0.00	0.01	0.00
Nonvb. Intelligence	0.04	0.01	0.28^**	0.02	0.01	0.17
Anxiety	−0.01	0.00	−0.19⁺	−0.01	0.00	−0.26^*
Domain specific STM (T1)	0.32	0.07	0.46^***	0.25	0.09	0.35^**
R²(ΔF)	0.57 (23.18^***)			0.37 (7.98^**)
STEP 6
Intercept	−0.86	0.40	–	−0.25	0.41	–
Age	0.01	0.01	0.12	0.00	0.01	0.09
Gender	0.17	0.09	0.16	−0.01	0.01	−0.01
Nonvb. Intelligence	0.04	0.01	0.27^**	0.02	0.01	0.19
Anxiety	−0.01	0.00	−0.19^*	−0.01	0.00	−0.20
Domain specific STM (T1)	0.31	0.07	0.44^***	0.22	0.09	0.30^*
Domain non-specific STM (T1)	0.07	0.09	0.09	0.12	0.07	0.20
R²(ΔF)	0.57 (0.69)			0.41 (2.99)
STEP 7
Intercept	−0.95	0.44	–	−0.28	0.40	–
Age	0.00	0.01	0.11	0.00	0.01	0.09
Gender	0.17	0.10	0.16	−0.01	0.09	−0.01
Nonvb. Intelligence	0.03	0.01	0.26^*	0.02	0.01	0.15
Anxiety	−0.01	0.00	−0.18	−0.01	0.00	−0.20
Domain specific STM (T1)	0.24	0.14	0.34	0.10	0.10	0.14
Domain non-specific STM (T1)	0.08	0.09	0.10	0.09	0.07	0.15
Domain specific STM (T2)	0.09	0.17	0.11	0.18	0.08	0.30^*
R²(ΔF)	0.58 (0.29)			0.46 (4.89^**)
STEP 8
Intercept	−0.99	0.44	–	−0.48	0.43	–
Age	0.00	0.01	0.10	0.00	0.01	0.06
Gender	0.18	0.10	0.17	0.01	0.01	0.01
Nonvb. Intelligence	0.03	0.01	0.24^*	0.01	0.01	0.10
Anxiety	−0.01	0.00	−0.18	−0.00	0.00	−0.18
Domain specific STM (T1)	0.21	0.14	0.30	0.11	0.10	0.16
Domain non-specific STM (T1)	0.03	0.10	0.04	−0.06	0.14	−0.10
Domain specific STM (T2)	0.12	0.17	0.14	0.20	0.08	0.32^*
Domain non-specific STM (T2)	0.08	0.09	0.12	0.20	0.17	0.29
R²(ΔF)	0.58 (0.98)			0.47 (1.46)

β, Standardized regression coefficient; T1, first time assessment; T2, second time assessment; Domain specific STM, verbal STM for verbal WM, and visuospatial STM for visuospatial WM. Domain non-specific STM, visuospatial STM for verbal WM, and verbal STM for visuospatial WM. The baseline gender is male.

⁺

p < 0.06,

p < 0.05,

^**

p < 0.01,

^***

p < 0.001.