@article{ref1,
title="Hemodynamic and behavioral changes in older adults during cognitively demanding dual tasks",
journal="Brain and behavior",
year="2021",
author="Fraser, Sarah and Lajoie, Yves and St-Amant, Gabrielle and Michaud, Lucas and Polskaia, Nadia and Tobón Vallejo, Diana and Salzman, Talia",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="INTRODUCTION: Executive functions play a fundamental role in walking by integrating information from cognitive-motor pathways. Subtle changes in brain and behavior may  help identify older adults who are more susceptible to executive function deficits  with advancing age due to prefrontal cortex deterioration. This study aims to  examine how older adults mitigate executive demands while walking during cognitively  demanding tasks. <br><br>METHODS: Twenty healthy older adults (M = 71.8 years, SD = 6.4)  performed simple reaction time (SRT), go/no-go (GNG), n-back (NBK), and double  number sequence (DNS) cognitive tasks of increasing difficulty while walking (i.e.,  dual task). Functional near infra-red spectroscopy (fNIRS) was used to measure the  hemodynamic response (i.e., oxy- [HbO2] and deoxyhemoglobin [HbR]) changes in the  prefrontal cortex (PFC) during dual and single tasks (i.e., walking alone). In  addition, performance was measured using gait speed (m/s), response time (s), and  accuracy (% correct). <br><br>RESULTS: Using repeated measures ANOVAs, neural findings  demonstrated a main effect of task such that ∆HbO2 (p = .047) and ∆HbR (p = .040)  decreased between single and dual tasks. An interaction between task and cognitive  difficulty (p = .014) revealed that gait speed decreased in the DNS between single  and dual tasks. A main effect of task in response time indicated that the SRT  response time was faster than all other difficulty levels (p < .001). Accuracy  performance declined between single and dual tasks (p = .028) and across difficulty  levels (p < .001) but was not significantly different between the NBK and DNS. <br><br>CONCLUSION: Findings suggest that a healthy older adult sample might mitigate  executive demands using an automatic locomotor control strategy such that shifting  conscious attention away from walking during the dual tasks resulted in decreased  ∆HbO2 and ∆HbR. However, decreased prefrontal activation was inefficient at  maintaining response time and accuracy performance and may be differently affected  by increasing cognitive demands.<p /> <p>Language: en</p>",
language="en",
issn="2162-3279",
doi="10.1002/brb3.2021",
url="http://dx.doi.org/10.1002/brb3.2021"
}