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)
Tract	Human (mean ± SD)	Vervet (mean ± SD)	Macaque (mean ± SD)	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.