Table 2.
Observed Mean (SD) Structure Volumes and Statistical Tests between Groups*
| Brain Measure | Control | Far | Mid | Near | F | Degrees of Freedom1 | p | contrasts |
|---|---|---|---|---|---|---|---|---|
| Total Brain Tissue | 1242.3 (133.6) | 1215.5 (130.1) | 1182.4 (121.1) | 1152.6 (129.7) | 73.16 | 3, 641 | <0.0001 | C>F>M>N |
| CSF | 110.30 (47.92) | 110.62 (39.09) | 137.72 (47.94) | 174.99 (61.04) | 73.49 | 3, 641 | <0.0001 | C>F>M>N |
| Cortical Gray Matter | 600.47 (64.79) | 585.32 (61.97) | 576.98 (56.30) | 570.20 (59.60) | 10.32 | 3, 643 | <0.0001 | C>(F,M)>N |
| Cerebral White Matter | 439.48 (59.77) | 428.96 (57.13) | 410.70 (57.60) | 388.33 (64.50) | 50.83 | 3, 644 | <0.0001 | C>F>M>N |
| Cerebellum | 116.52 (13.92) | 116.49 (14.73) | 112.89 (12.17) | 115.90 (13.00) | 3.21 | 3, 650 | 0.02 | ns |
| Thalamus | 11.76 (1.36) | 11.53 (1.32) | 10.90 (1.47) | 10.00 (1.60) | 44.73 | 3, 644 | <0.0001 | C>(F,M)>N |
| Caudate | 7.21 (1.19) | 6.62 (1.15) | 5.72 (1.13) | 4.73 (1.30) | 120.86 | 3, 635 | <0.0001 | C>F>M>N |
| Putamen | 9.81 (1.19) | 9.22 (1.25) | 8.08 (1.29) | 6.99 (1.25) | 148.08 | 3, 641 | <0.0001 | C>F>M>N |
| Total Striatum | 17.03 (2.12) | 15.82 (2.23) | 13.79 (2.23) | 11.71 (2.43) | 166.10 | 3, 634 | <0.0001 | C>F>M>N |
*
Means and (standard deviations) presented are for unadjusted volumes.
Statistical analyses computed on volumes adjusted for Intracranial Volume (ICV) Ratios, age and gender. Denominator degrees of freedom vary due to Satterthwaite approximations and slight sample size fluctuation from measurement failure. Sample size was 649 for caudate and total striatum, 657 for all other measure