Table 2.

Normative scaling relationships between cerebellar volumes and aTBV

Structure	Allometric scaling with aTBV		Male offset		Sex interaction		R²
Structure	β₁-coefficient (SE)	p (for null coefficient = 1)	β₂-coefficient (SE)	p	β₃-coefficient (SE)	p	R²
TCbV	0.60 (0.061)	1.23E-09	0.017 (0.002)	0.002			0.66
Regions
Hemispheres	0.61 (0.062)	5.04E-09	0.018 (0.006)	0.002			0.66
Vermis	0.56 (0.072)	2.04E-08					0.35
Flocculus	0.39 (0.100)	1.86E-08	0.032 (0.009)	0.001			0.38
Lobes
Anterior	0.93 (0.166)	0.679	2.85 (1.340)	0.036	−0.47 (0.220)^*	0.036	0.36
Superior posterior	0.53 (0.064)	4.97E-11	0.015 (0.006)	0.012			0.58
Inferior Posterior	0.84 (0.079)	0.041	0.019 (0.007)	0.012			0.67
Lobules
Lobule III	0.59 (0.121)	0.0011					0.17
Lobule IV	0.61 (0.126)	0.0024					0.17
Lobule V	0.72 (0.087)	0.0017					0.38
Lobule VI	0.63 (0.086)	2.99E-05					0.32
Crus I	0.66 (0.072)	8.47E-06					0.43
Crus II	0.36 (0.091)	1.18E-10	0.031 (0.008)	2.79E-04			0.39
Lobule VIIB	0.59 (0.088)	9.54E-06	0.022 (0.008)	0.006			0.51
Lobule VIIIA	0.73 (0.083)	0.0016	0.021 (0.008)	0.008			0.61
Lobule VIIIB	0.90 (0.093)	0.274	0.017 (0.009)	0.042			0.62
Lobule IX	1.04 (0.118)	0.727					0.41

Bold entries highlight regions with statistically significant evidence against the null hypotheses of isometric scaling and/or equivalent intercepts/slopes between males and females.
↵*Coefficient measures the difference in scaling coefficient between males and females. Thus, anterior lobe volume scales isometrically with aTBV in females (coefficient = 0.93, no statistically significant difference from 1) but hypoallometrically with aTBV in males [coefficient = 0.46 (i.e., 0.93–0.47), significantly different from the female coefficient (p = 0.036) and from the isometric null coefficient of 1 (p = 0.002)].

The Journal of Neuroscience Society for Neuroscience

Allometric Analysis Detects Brain Size-Independent Effects of Sex and Sex Chromosome Complement on Human Cerebellar Organization