title: Overrecruitment in the aging brain as a function of task demands: evidence for a compensatory view.
abstract: This study used fMRI to investigate the neural effects of increasing cognitive demands in normal aging and their role for performance. Simple and complex go/no-go tasks were used with two versus eight colored letters as go stimuli, respectively. In both tasks, no-go stimuli could produce high conflict (same letter, different color) or low conflict (colored numbers) with go stimuli. Multivariate partial least square analysis of fMRI data showed that older adults overengaged a cohesive pattern of fronto-parietal regions with no-go stimuli under the specific combination of factors which progressively amplified task demands: high conflict no-go trials in the first phase of the complex task. This early neural overrecruitment was positively correlated with a lower error rate in the older group. Thus, the present data suggest that age-related extra-recruitment of neural resources can be beneficial for performance under taxing task conditions, such as when novel, weak, and complex rules have to be acquired.
authors.affiliation: Cognitive Neuroscience Sector, SISSA (International School for Advanced Studies), Trieste, Italy. vallesi@sissa.it
authors.forename: Antonino
authors.initials: A
authors.lastname: Vallesi
authors.forename: Anthony R
authors.initials: AR
authors.lastname: McIntosh
authors.forename: Donald T
authors.initials: DT
authors.lastname: Stuss
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D003118:Color Perception; D003220:Conflict, Psychological; D003657:Decision Making; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time; D055815:Young Adult
chemical_list: D010100:Oxygen