Table 5.
Proportional and absolute volume measurements of frontal association tracts between species
| Tract | Human (mean ± SD) | Vervet (mean ± SD) | Macaque (mean ± SD) |
Post hoc comparisons (p values) |
||
|---|---|---|---|---|---|---|
| Human versus vervet | Human versus macaque | Vervet versus macaque | ||||
| Cingulum | ||||||
| Proportion (%) | 4.06 ± 0.62 | 3.21 ± 0.29 | 3.04 ± 0.23 | |||
| Absolute (ml) | 23.28 ± 3.35 | 0.79 ± 0.10 | 0.85 ± 0.16 | <0.001 | <0.001 | 0.760 |
| UF | ||||||
| Proportion | 2.56 ± 0.69 | 2.38 ± 0.39 | 1.97 ± 0.53 | |||
| Absolute | 14.86 ± 4.11 | 0.58 ± 0.08 | 0.56 ± 0.20 | <0.001 | <0.001 | 0.971 |
| FAT | ||||||
| Proportion | 3.37 ± 1.00 | 2.35 ± 0.86 | 2.47 ± 0.92 | |||
| Absolute | 19.26 ± 5.19 | 0.59 ± 0.24 | 0.71 ± 0.34 | <0.001 | <0.001 | 0.812 |
| SLF I | ||||||
| Proportion | 3.46 ± 0.93 | 0.71 ± 0.36 | 1.22 ± 0.44 | <0.001 | 0.001 | 0.225 |
| Absolute | 20.00 ± 5.85 | 0.17 ± 0.09 | 0.35 ± 0.15 | <0.001 | <0.001 | 0.142 |
| SLF II | ||||||
| Proportion | 3.66 ± 1.17 | 1.12 ± 0.36 | 1.06 ± 0.55 | <0.001 | <0.001 | 0.986 |
| Absolute | 20.96 ± 6.09 | 0.27 ± 0.07 | 0.31 ± 0.18 | <0.001 | <0.001 | 0.902 |
| SLF III | ||||||
| Proportion | 3.65 ± 1.08 | 1.33 ± 0.06 | 1.54 ± 1.02 | <0.001 | 0.060 | 0.816 |
| Absolute | 21.07 ± 6.40 | 0.33 ± 0.05 | 0.46 ± 0.33 | <0.001 | <0.001 | 0.695 |
| IFOF | ||||||
| Proportion | 9.59 ± 1.22 | 3.80 ± 0.89 | 3.25 ± 0.94 | <0.001 | <0.001 | 0.656 |
| Absolute | 55.34 ± 8.73 | 0.95 ± 0.30 | 0.92 ± 0.33 | <0.001 | <0.001 | 0.989 |
| AF | ||||||
| Proportion | 8.96 ± 1.38 | 1.58 ± 0.11 | 1.45 ± 0.13 | <0.001 | <0.001 | 0.044 |
| Absolute | 52.07 ± 10.88 | 0.39 ± 0.03 | 0.40 ± 0.05 | <0.001 | <0.001 | 0.832 |
Individual frontal association tracts (cingulum; UF; FAT; SLF I, II, and III; IFOF; and AF) 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 in cases where signficant species-driven differences were observed with Welch's ANOVA. See results for ANOVA statistics.