title: Distinct aspects of frontal lobe structure mediate age-related differences in fluid intelligence and multitasking.
abstract: Ageing is characterized by declines on a variety of cognitive measures. These declines are often attributed to a general, unitary underlying cause, such as a reduction in executive function owing to atrophy of the prefrontal cortex. However, age-related changes are likely multifactorial, and the relationship between neural changes and cognitive measures is not well-understood. Here we address this in a large (N=567), population-based sample drawn from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) data. We relate fluid intelligence and multitasking to multiple brain measures, including grey matter in various prefrontal regions and white matter integrity connecting those regions. We show that multitasking and fluid intelligence are separable cognitive abilities, with differential sensitivities to age, which are mediated by distinct neural subsystems that show different prediction in older versus younger individuals. These results suggest that prefrontal ageing is a manifold process demanding multifaceted models of neurocognitive ageing.
authors.affiliation: MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 7EF, UK.
authors.forename: Rogier A
authors.initials: RA
authors.lastname: Kievit
authors.affiliation: Department of Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK.
authors.forename: Simon W
authors.initials: SW
authors.lastname: Davis
authors.affiliation: MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 7EF, UK.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Mitchell
authors.affiliation: 1] MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 7EF, UK [2] School of Psychological Sciences, The University of Manchester, Brunswick Street, Manchester M13 9PL, UK.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Taylor
authors.affiliation: MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 7EF, UK.
authors.forename: John
authors.initials: J
authors.lastname: Duncan
authors.affiliation: MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 7EF, UK.
authors.forename: Richard N A
authors.initials: RN
authors.lastname: Henson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001284:Atrophy; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D066128:Gray Matter / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000473:pathology / Q000502:physiology*; D013647:Task Performance and Analysis; D066127:White Matter / Q000033:anatomy & histology / Q000502:physiology