Table 3.
Proportional and absolute frontal volume measurements between species
| Volume measures | Human (mean ± SD) | Vervet (mean ± SD) | Macaque (mean ± SD) |
Post hoc comparisons (p values) |
||
|---|---|---|---|---|---|---|
| Human versus vervet | Human versus macaque | Vervet versus macaque | ||||
| Frontal Cortex (voxel-based) | ||||||
| Proportion (%) | 32.69 ± 0.79 | 28.89 ± 0.79 | 29.12 ± 1.22 | 0.002 | 0.004 | 0.938 |
| Absolute (ml) | 95.27 ± 8.45 | 2.68 ± 0.13 | 3.16 ± 0.57 | <0.001 | <0.001 | 0.271 |
| Frontal white matter (voxel-based) | ||||||
| Proportion | 40.80 ± 0.62 | 23.33 ± 0.72 | 23.19 ± 1.04 | <0.001 | <0.001 | 0.974 |
| Absolute | 96.69 ± 7.93 | 2.33 ± 0.19 | 2.92 ± 0.59 | <0.001 | <0.001 | 0.182 |
| Frontal tracts (tractography) | ||||||
| Proportion | 66.18 ± 2.56 | 48.16 ± 2.94 | 47.98 ± 4.54 | 0.001 | 0.001 | 0.997 |
| Absolute | 382.60 ± 45.30 | 11.91 ± 2.04 | 13.48 ± 2.80 | <0.001 | <0.001 | 0.618 |
| Anterior commissure (tractography) | ||||||
| Proportion | 4.59 ± 1.15 | 9.90 ± 1.30 | 7.86 ± 1.80 | 0.004 | 0.028 | 0.091 |
| Absolute | 26.73 ± 7.91 | 2.46 ± 0.56 | 2.18 ± 0.56 | <0.001 | <0.001 | 0.754 |
Frontal and nonfrontal (anterior commissure) volume measures in humans (n = 20), vervets (n = 4), and macaques (n = 5). Descriptive statistics and Games-Howell post hoc comparisons between species are given for proportional (normalized by total volume for each measure) and absolute volumes. See Results for Welch's ANOVA statistics.