Table 3.

Results from regression analyses with raw volumes

	Regression with age				Regression with age and age2
	β	F	p	R2	F	p	R2	p age2a
Cerebral cortex	−0.60	95.42	3.78E-18	0.36	51.91	2.79E-18	0.38	0.018
Cerebral WM	0.41	34.93	1.84E-8	0.17	20.84	8.25E-9	0.20	0.018
Hippocampus	0.12	2.35	0.127	0.01	3.11	0.047	0.04	0.052
Amygdala	0.16	4.32	0.039	0.03	3.97	0.021	0.05	0.061
Caudate	−0.21	8.13	0.005	0.05	4.56	0.012	0.05	0.324
Putamen	−0.38	28.12	3.54E-7	0.14	13.98	2.43E-6	0.14	0.956
Pallidum	−0.32	18.66	2.65E-5	0.10	9.42	1.33E-4	0.10	0.612
Accumbens	−0.30	16.90	6.15E-5	0.09	9.88	8.82E-5	0.11	0.103
Thalamus	−0.02	0.04	0.849	2.16E-4	0.08	0.925	0.001	0.731
Cerebellum GM	−0.26	11.89	0.001	0.07	7.01	0.001	0.08	0.154
Cerebellum WM	0.35	23.48	2.84E-6	0.12	18.37	6.12E-8	0.18	0.001
Brainstem	0.37	26.55	7.09E-7	0.14	17.67	1.08E-7	0.17	0.006
Lateral ventricle	0.34	21.56	6.87E-6	0.11	10.99	3.28E-5	0.12	0.489
Inferior lateral ventricle	−0.07	0.94	0.335	0.01	0.47	0.628	0.01	0.955
Third ventricle	0.09	1.38	0.241	0.01	1.76	0.176	0.02	0.147
Fourth ventricle	−9.52E-4	1.53E-4	0.990	9.06E-7	0.01	0.988	1.38E-4	0.880

Results shown are from two separate regression analyses with raw volumes, one with only age as the predictor variable and the other with both age and age² as predictor variables. Bold characters for R² indicate a statistically significant quadratic age relationship.

^aThe p value for the unique contribution of age² to the explained variance in brain volume.