title: Age-related differences in the structural complexity of subcortical and ventricular structures.
abstract: It has been well established that the volume of several subcortical structures decreases in relation to age. Different metrics of cortical structure (e.g., volume, thickness, surface area, and gyrification) have been shown to index distinct characteristics of interindividual differences; thus, it is important to consider the relation of age to multiple structural measures. Here, we compare age-related differences in subcortical and ventricular volume to those differences revealed with a measure of structural complexity, quantified as fractal dimensionality. Across 3 large data sets, totaling nearly 900 individuals across the adult lifespan (aged 18-94 years), we found greater age-related differences in complexity than volume for the subcortical structures, particularly in the caudate and thalamus. The structural complexity of ventricular structures was not more strongly related to age than volume. These results demonstrate that considering shape-related characteristics improves sensitivity to detect age-related differences in subcortical structures.
authors.affiliation: Department of Psychology, Boston College, Chestnut Hill, MA, USA. Electronic address: madanc@bc.edu.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Madan
authors.affiliation: Department of Psychology, Boston College, Chestnut Hill, MA, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Kensinger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D002421:Caudate Nucleus / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology*; D002552:Cerebral Ventricles / Q000473:pathology*; D066264:Datasets as Topic; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011699:Putamen / Q000473:pathology; D013788:Thalamus / Q000473:pathology; D055815:Young Adult
keywords: Age; Atrophy; Brain morphometry; Fractal dimensionality; Hippocampus; Putamen; Thalamus; Ventricles