title: A neuroimaging investigation of the association between aerobic fitness, hippocampal volume, and memory performance in preadolescent children.
abstract: Because children are becoming overweight, unhealthy, and unfit, understanding the neurocognitive benefits of an active lifestyle in childhood has important public health and educational implications. Animal research has indicated that aerobic exercise is related to increased cell proliferation and survival in the hippocampus as well as enhanced hippocampal-dependent learning and memory. Recent evidence extends this relationship to elderly humans by suggesting that high aerobic fitness levels in older adults are associated with increased hippocampal volume and superior memory performance. The present study aimed to further extend the link between fitness, hippocampal volume, and memory to a sample of preadolescent children. To this end, magnetic resonance imaging was employed to investigate whether higher- and lower-fit 9- and 10-year-old children showed differences in hippocampal volume and if the differences were related to performance on an item and relational memory task. Relational but not item memory is primarily supported by the hippocampus. Consistent with predictions, higher-fit children showed greater bilateral hippocampal volumes and superior relational memory task performance compared to lower-fit children. Hippocampal volume was also positively associated with performance on the relational but not the item memory task. Furthermore, bilateral hippocampal volume was found to mediate the relationship between fitness level (VO(2) max) and relational memory. No relationship between aerobic fitness, nucleus accumbens volume, and memory was reported, which strengthens the hypothesized specific effect of fitness on the hippocampus. The findings are the first to indicate that aerobic fitness may relate to the structure and function of the preadolescent human brain.
authors.affiliation: Department of Psychology & Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Chaddock
authors.forename: Kirk I
authors.initials: KI
authors.lastname: Erickson
authors.forename: Ruchika Shaurya
authors.initials: RS
authors.lastname: Prakash
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Kim
authors.forename: Michelle W
authors.initials: MW
authors.lastname: Voss
authors.forename: Matt
authors.initials: M
authors.lastname: Vanpatter
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Pontifex
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Raine
authors.forename: Alex
authors.initials: A
authors.lastname: Konkel
authors.forename: Charles H
authors.initials: CH
authors.lastname: Hillman
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Cohen
authors.forename: Arthur F
authors.initials: AF
authors.lastname: Kramer
mesh_terms: D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology; D001931:Brain Mapping; D002153:Calorimetry, Indirect / Q000379:methods; D002648:Child; D015444:Exercise / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000033:anatomy & histology* / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D008954:Models, Biological; D009483:Neuropsychological Tests; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D013223:Statistics as Topic