Gender Differences in Cerebral Cortical Folding: Multivariate Complexity-Shape Analysis with Insights into Handling Brain-Volume Differences

Abstract

Abstract. This paper presents a study of gender differences in adult human cerebral cortical folding patterns. The study employs a new multivariate statistical descriptor for analyzing folding patterns in a region of interest (ROI) and a rigorous nonparametric permutation-based scheme for hypothesis testing. Unlike typical ROI-based methods that summarize folding complexity or shape by single/few numbers, the proposed descriptor systematically constructs a unified description of complexity and shape in a high-dimensional space (thousands of numbers/dimensions). Furthermore, this paper presents new mathematical insights into the relationship of intra-cranial volume (ICV) with cortical complexity and shows that conventional complexity descriptors implicitly handle ICV differences in different ways, thereby lending different meanings to "complexity". This paper describes two systematic methods for handling ICV changes in folding studies using the proposed descriptor. The clinical study in this paper exploits these theoretical insights to demonstrate that (i) the answer to which gender has higher/lower "complexity" depends on how a folding measure handles ICV differences and (ii) cortical folds in males and females differ significantly in shape as well.

A tract-specific framework for white matter morphometry combining macroscopic and microscopic tract features

“…Finally, statistical analysis involves the analyses of shape and microstructure both individually and jointly. The latter employs a novel multivariate inference technique based on the analysis of the joint probability density function (pdf) of the feature set whose efficacy has been demonstrated in a cortical folding study of neonatal brains using the joint analysis of folding complexity and shape indices (Awate et al, 2009b,a). In the following, we discuss each component in detail.…”

“…In addition, we utilize a novel multivariate analysis (Awate et al, 2009b,a) to directly exploit the relationship between thickness and diffusion properties. Specifically, for each subject, we build a joint probability density function (pdf) of thickness and diffusion properties which captures the interdependencies of thickness and diffusion features as provided solely by the data.…”

Local cortical surface complexity maps from spherical harmonic reconstructions

“…The FD can also be applied to measure cortical folding complexity, and previous studies have shown significant differences in regional FD for psychiatric disorders such as schizophrenia (Casanova et al, 1989;Narr et al, 2004;Narr et al, 2001), obsessive-compulsive disorder (Ha et al, 2005), epilepsy (Free et al, 1996), Alzheimer's disease (King et al, 2009(King et al, , 2010, multiple sclerosis (Esteban et al, 2007s, 2009, cerebellar degeneration , stroke (Zhang et al, 2008a), autism (Awate et al, 2008), and Williams syndrome (Thompson et al, 2005), as well as for normal development (Awate et al, 2010;Blanton et al, 2001;Kalmanti and Maris, 2007;Shyu et al, 2010;Wu et al, 2009), early-life blindness (Zhang et al, 2008b), and IQ (Im et al, 2006). Furthermore, some studies report local FD or folding differences for genetic factors such as 22q11 deletion syndrome (Schaer et al, 2008), gender (Awate et al, 2009;Luders et al, 2004), and brain size (Toro et al, 2008).…”

Age‐ and gender‐related regional variations of human brain cortical thickness, complexity, and gradient in the third decade

“…CC increases in the early life, with regional differences in a caudo‐rostral gradient, and then undergoes a progressive decrease [Blanton et al, ; Magnotta et al, ; Zilles et al, 1988]. As reported, CC is greater in women frontal and parietal lobes [Awate et al, ; Luders et al, 2004, ,b, 2008; Nopoulos et al, ; Zilles et al, ].…”