Table 4.
Proportional and absolute frontal tract group volume measurements between species
| Tract group | Human (mean ± SD) | Vervet (mean ± SD) | Macaque (mean ± SD) |
Post hoc comparisons (p values) |
||
|---|---|---|---|---|---|---|
| Human versus vervet | Human versus macaque | Vervet versus macaque | ||||
| Association | ||||||
| Proportion (%) | 36.69 ± 3.13 | 25.92 ± 3.48 | 23.15 ± 6.46 | 0.010 | 0.018 | 0.706 |
| Absolute (ml) | 211.92 ± 27.19 | 6.36 ± 0.92 | 6.64 ± 2.52 | <0.001 | <0.001 | 0.972 |
| Commissural | ||||||
| Proportion | 34.58 ± 3.30 | 27.85 ± 3.67 | 26.19 ± 5.76 | 0.002 | 0.014 | 0.989 |
| Absolute | 200.42 ± 32.31 | 6.93 ± 1.67 | 7.42 ± 2.22 | <0.001 | <0.001 | 0.924 |
| Projection | ||||||
| Proportion | 14.52 ± 1.44 | 4.80 ± 1.82 | 5.14 ± 2.25 | 0.001 | 0.001 | 0.937 |
| Absolute | 83.60 ± 9.78 | 1.22 ± 0.59 | 1.50 ± 0.78 | <0.001 | <0.001 | 0.818 |
| Intrafrontal | ||||||
| Proportion | 16.33 ± 1.77 | 9.50 ± 0.73 | 7.79 ± 1.04 | <0.001 | <0.001 | 0.055 |
| Absolute | 94.53 ± 14.68 | 2.34 ± 0.34 | 2.17 ± 0.45 | <0.001 | <0.001 | 0.806 |
Association, commissural, projection, and intrafrontal tract group volumes 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.