Characterizing inter-individual differences in brain morphology
Christopher R. Madan1,2; 1University of Nottingham, 2Boston College
The most defining feature of the human brain is its folding structure; the underlying principle of these cortical folds has been a long-standing topic of investigation and continues to be a mystery. Despite this, there are general inter-individual consistencies in the macroscopic organization of cortical folds, and these consistencies form the basis of use of cortical parcellation atlases. Standard measures of cortical morphology, however, often quantify volumetric properties of the cortex (i.e., volume, thickness, surface area) rather than shape-related characteristics. An exception, however, is the quantification of gyrification. Nonetheless, several studies have observed that a mathematical measure, fractal dimensionality, is more sensitive to inter-individual differences in brain morphology than extant measures, including gyrification. Here I present results demonstrating that fractal dimensionality is useful in characterizing age-related changes in brain structure for both cortical and subcortical structures. Further analyses compare fractal dimensionality with more distinct measures of shape such as the power spectra of cortical folding (i.e., different spatial frequencies in cortical folding) and subcortical surface-to-volume ratio and surface texture. On-going work further evaluates the utility of these shape measures as a biomarkers for dementia.
Topic Area: NEUROANATOMY