Table 3. Age-matched group differences in brain volume measures.

	Caucasian (N = 31)	African-American (N = 25)	F value	p value
Total Cerebrum	1173.4 (119.4)	1076.0 (67.9)	16.60	0.0002
GM+WM/CSF Ratio	680.9 (89.5)	629.8 (54.8)	12.86	0.0008
Lateral Ventricles	20.1 (11.26)	15.2 (5.0)	0.02	0.8782
	0.017 (0.009)	0.014 (0.004)	1.07	0.3064
Total Gray Matter	678.6 (89.5)	627.2 (54.5)	2.92	0.0938
	0.580 (0.063)	0.584 (0.048)	0.48	0.4925
Total White Matter	450.7 (68.0)	429.6 (62.1)	2.19	0.1453
	0.385 (0.048)	0.398 (0.044)	1.71	0.1965
Amygdala, L	2.3 (0.5)	2.2 (0.5)	2.32	0.1341
	0.0019 (0.0004)	0.0021 (0.0004)	4.47	0.0396
Amygdala, R	2.3 (0.5)	2.2 (0.4)	1.76	0.1912
	0.0019 (0.0004)	0.0021 (0.0004)	5.50	0.0231
Caudate, L	4.1 (0.7)	3.8 (0.5)	1.94	0.1701
	0.0035 (0.0006)	0.0036 (0.0005)	0.03	0.8670
Caudate, R	4.4 (0.7)	4.1 (0.6)	2.34	0.1324
	0.0038 (0.0006)	0.0039 (0.0005)	0.29	0.5947
Hippocampus, L	3.7 (0.5)	3.5 (0.5)	0.64	0.4266
	0.0032 (0.0005)	0.0032 (0.0004)	0.01	0.9142
Hippocampus, R	3.6 (0.6)	3.5 (0.5)	0.01	0.9118
	0.0031 (0.0005)	0.0033 (0.0005)	1.23	0.2734
Orbitofrontal Cortex, L	7.0 (2.2)	7.8 (1.7)	6.06	0.0174
	0.0059 (0.0016)	0.0072 (0.0016)	7.85	0.0072
Orbitofrontal Cortex, R	7.9 (1.6)	8.3 (1.7)	2.74	0.1040
	0.0068 (0.0013)	0.0077 (0.0016)	5.61	0.0216

The top measure for each region is the mean volume (mLs) and the bottom measure is the ratio of regional volume/cerebrum (defined as GM+WM+CSF). Standard deviation is in parentheses. Each variable has 1 df, with 55 df for each model.