title: The Neurocognitive Basis for Impaired Dual-Task Performance in Senior Fallers.
abstract: Falls are a major health-care concern, and while dual-task performance is widely recognized as being impaired in those at-risk for falls, the underlying neurocognitive mechanisms remain unknown. A better understanding of the underlying mechanisms could lead to the refinement and development of behavioral, cognitive, or neuropharmacological interventions for falls prevention. Therefore, we conducted a cross-sectional study with community-dwelling older adults aged 70-80 years with a history of falls (i.e., two or more falls in the past 12 months) or no history of falls (i.e., zero falls in the past 12 months); n = 28 per group. We compared functional activation during cognitive-based dual-task performance between fallers and non-fallers using functional magnetic resonance imaging (fMRI). Executive cognitive functioning was assessed via Stroop, Trail Making, and Digit Span. Mobility was assessed via the Timed Up and Go test (TUG). We found that non-fallers exhibited significantly greater functional activation compared with fallers during dual-task performance in key regions responsible for resolving dual-task interference, including precentral, postcentral, and lingual gyri. Further, we report slower reaction times during dual-task performance in fallers and significant correlations between level of functional activation and independent measures of executive cognitive functioning and mobility. Our study is the first neuroimaging study to examine dual-task performance in fallers, and supports the notion that fallers have reduced functional brain activation compared with non-fallers. Given that dual-task performance-and the underlying neural concomitants-appears to be malleable with relevant training, our study serves as a launching point for promising strategies to reduce falls in the future.
authors.affiliation: Department of Psychology, University of British Columbia Vancouver, BC, Canada.
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Nagamatsu
authors.affiliation: Department of Physical Therapy, University of British ColumbiaVancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British ColumbiaVancouver, BC, Canada.
authors.forename: C Liang
authors.initials: CL
authors.lastname: Hsu
authors.affiliation: Department of Psychology, University of Iowa Iowa City, IA, USA.
authors.forename: Michelle W
authors.initials: MW
authors.lastname: Voss
authors.affiliation: Department of Physical Therapy, University of British Columbia Vancouver, BC, Canada.
authors.forename: Alison
authors.initials: A
authors.lastname: Chan
authors.affiliation: Faculty of Medicine, University of British Columbia Vancouver, BC, Canada.
authors.forename: Niousha
authors.initials: N
authors.lastname: Bolandzadeh
authors.affiliation: Department of Psychology, University of British Columbia Vancouver, BC, Canada.
authors.forename: Todd C
authors.initials: TC
authors.lastname: Handy
authors.affiliation: Department of Psychology, University of British Columbia Vancouver, BC, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Graf
authors.affiliation: Division of Geriatric Medicine, Faculty of Medicine, University of British Columbia Vancouver, BC, Canada.
authors.forename: B Lynn
authors.initials: BL
authors.lastname: Beattie
authors.affiliation: Department of Physical Therapy, University of British ColumbiaVancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British ColumbiaVancouver, BC, Canada.
authors.forename: Teresa
authors.initials: T
authors.lastname: Liu-Ambrose
keywords: aging neuroscience; dual-task; fMRI; fallers; falls risk