@article{91fd32f56dd0458898480e1460785aac,
title = "Prefrontal cortex involvement during dual-task stair climbing in healthy older adults: An fNIRS study",
abstract = "Executive function and motor control deficits adversely affect gait performance with age, but the neural correlates underlying this interaction during stair climbing remains unclear. Twenty older adults (72.7 ± 6.9 years) completed single tasks: standing and responding to a response time task (SC), ascending or descending stairs (SMup, SMdown); and a dual-task: responding while ascending or descending stairs (DTup, DTdown). Prefrontal hemodynamic response changes (∆HbO2, ∆HbR) were examined using functional near-infrared spectroscopy (fNIRS), gait speed was measured using in-shoe smart insoles, and vocal response time and accuracy were recorded. Findings revealed increased ∆HbO2 (p = 0.020) and slower response times (p < 0.001) during dual-versus single tasks. ∆HbR (p = 0.549), accuracy (p = 0.135) and gait speed (p = 0.475) were not significantly different between tasks or stair climbing conditions. ∆HbO2 and response time findings suggest that executive processes are less efficient during dual-tasks. These findings, in addition to gait speed and accuracy maintenance, may provide insights into the neural changes that precede performance declines. To capture the subtle differences between stair ascent and descent and extend our understanding of the neural correlates of stair climbing in older adults, future studies should examine more difficult cognitive tasks.",
keywords = "Cognitive aging, Cognitive function, Executive function, Functional near-infrared spectroscopy (fNIRS), Gait, Neuroimaging, Older adult, Prefrontal cortex (PFC), Stair climbing",
author = "Talia Salzman and Ahmed Aboualmagd and Hawazin Badawi and Diana Tob{\'o}n-Vallejo and Hyejun Kim and Lama Dahroug and Fedwa Laamarti and {El Saddik}, Abdulmotaleb and Sarah Fraser",
note = "Funding Information: Brain activation during stair ambulation has been scarcely examined due to the lim-tions associated with stationary neuroimaging techniques. However, with advancements itations associated with stationary neuroimaging techniques. However, with advance-in portable neuroimaging such as fNIRS, many overground walking studies have identified ments in portable neuroimaging such as fNIRS, many overground walking studies have that older adults exhibit increased brain activation during cognitive–motor dual-tasks [24]. identified that older adults exhibit increased brain activation during cognitive–motor Findings from this study support this; older adults exhibited bilateral PFC recruitment dual-tasks [24]. Findings from this study support this; older adults exhibited bilateral PFC given that there were no hemodynamic response differences across the individual fNIRS recruitment given that there were no hemodynamic response differences across the indi-channels or cerebral hemispheres. This is supported by STAC-r and neural compensa- vidual fNIRS channels or cerebral hemispheres. This is supported by STAC-r and neural tion models, which suggest that older adults demonstrate widespread PFC activation to compensation models, which suggest that older adults demonstrate widespread PFC ac-compensate for age-associated performance declines [31]. tivation to compensate for age-associated performance declines [31]. By examining the hemodynamic response across the whole PFC, there was a significant By examining the hemodynamic response across the whole PFC, there was a significant ∆HbO2 increase between the single and dual-tasks. This supports our initial hypothesis in that the competing demands of a cognitive and motor task required greater executive control compared to performing each one alone. Several studies examining cognitive performance have reported similar findings; pairing mental arithmetic [30,49], working memory [15,50], or verbal fluency tasks [45,46] with walking exercises resulted in greater reflect the challenges of stair ambulation, have also demonstrated increased PFC activation in older adults between single and dual-tasks [28,30,51]. Publisher Copyright: {\textcopyright} 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",
year = "2021",
month = jan,
doi = "10.3390/brainsci11010071",
language = "Ingl{\'e}s",
volume = "11",
pages = "1--14",
journal = "Brain Sciences",
issn = "2076-3425",
publisher = "MDPI Multidisciplinary Digital Publishing Institute",
number = "1",
}