title: Effects of reaction time variability and age on brain activity during Stroop task performance.
abstract: Variability in reaction time during task performance may reflect fluctuations in attention and cause reduced performance in goal-directed tasks, yet it is unclear whether the mechanisms behind this phenomenon change with age. Using fMRI, we tested young and cognitively healthy older adults with the Stroop task to determine whether aging affects the neural mechanisms underlying intra-individual reaction time variability. We found significant between-group differences in BOLD activity modulated by reaction time. In older adults, longer reaction times were associated with greater activity in frontoparietal attentional areas, while in younger adults longer reaction times were associated with greater activity in default mode network areas. Our results suggest that the neural correlates of reaction time variability change with healthy aging, reinforcing the concept of functional plasticity to maintain high cognitive function throughout the lifespan.
authors.affiliation: Centre for Neuroscience Studies, Queen's University, Botterell Hall, 18 Stuart Street, Kingston, ON, K7L 3N6, Canada. angela.tam@queensu.ca.
authors.forename: Angela
authors.initials: A
authors.lastname: Tam
authors.affiliation: Centre for Neuroscience Studies, Queen's University, Botterell Hall, 18 Stuart Street, Kingston, ON, K7L 3N6, Canada. 1al47@queensu.ca.
authors.forename: Angela C
authors.initials: AC
authors.lastname: Luedke
authors.affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, ON, K7L 3N6, Canada. 9jw62@queensu.ca.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Walsh
authors.affiliation: Departamento de Fisiologia, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Distrito Federal, C.P., 04510, Mexico. jfr@unam.mx.
authors.forename: Juan
authors.initials: J
authors.lastname: Fernandez-Ruiz
authors.affiliation: Centre for Neuroscience Studies, Queen's University, Botterell Hall, 18 Stuart Street, Kingston, ON, K7L 3N6, Canada. ag16@queensu.ca.|Department of Medicine (Geriatrics), Queen's University, St. Mary's of the Lake Hospital, 340 Union Street, Kingston, ON, K7L 5A2, Canada. ag16@queensu.ca.
authors.forename: Angeles
authors.initials: A
authors.lastname: Garcia
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology* / Q000523:psychology*; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology*; D057190:Stroop Test; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Aging; Attention; Performance variability; Reaction time; fMRI