Effects of tDCS of Dorsolateral Prefrontal Cortex on Dual-Task Performance Involving Manual Dexterity and Cognitive Task in Healthy Older Adults

Background. The ability to safely conduct different types of walking concurrently with a cognitive task (i.e., dual task) is crucial for daily life. The contribution of different walking types to dual-task performance has not yet been determined, nor is there agreement on the strategies that older adults use to divide their attention between two tasks (task prioritization).Objectives. To compare the effect of walking in three different directions (forward, backward, and sideways) on dual-task performance and to explore the strategies of older adults to allocate their attention in response to different motor task demands.Design. A cross-sectional study.Subjects. Thirty-two (22 female) community-dwelling older adults (aged72.7±5.7years).Methods. Subjects randomly conducted single and dual task: walking to three directions separately, cognitive tasks separately, and combination of the two.Results. Walking forward was the least demanding task, during single (FW < BW, SW) (P<.001) and dual tasks (FW < BW < SW) (P<.001). The calculation of DTC revealed the same pattern (P<.001). DTC of the cognitive tasks was not significantly different among the three walking types.Conclusions. The decline mainly in the motor performance during dual task indicates that participants prioritized the cognitive task. These findings challenge the “posture first” paradigm for task prioritization.

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Effects of motor and cognitive dual-task performance in depressive elderly, healthy older adults, and healthy young individuals

Dementia & Neuropsychologia ◽

10.1590/s1980-57642011dn05030007 ◽

2011 ◽

Vol 5 (3) ◽

pp. 198-202 ◽

Cited By ~ 4

Author(s):

Helena Moraes ◽

Andrea Deslandes ◽

Heitor Silveira ◽

Cynthia Arcoverde ◽

Heloisa Alve ◽

...

Keyword(s):

Older Adults ◽

Task Performance ◽

Dual Task ◽

Cycle Ergometer ◽

Memory Test ◽

Maximal Heart Rate ◽

Healthy Older Adults ◽

Cycle Ergometer Exercise ◽

Ergometer Exercise ◽

Dual Task Performance

Abstract Impairments in dual-task performance can be observed in healthy older adults when motor and cognitive assignments are applied simultaneously. According to the hypofrontality hypothesis, there may be a reduction in frontal cognitive function during exercise. Objective: The aim of the present study was to compare the performance changes on cognitive tests of depressive elderly (n=10), healthy older adults (n=10), and healthy young individuals (n=10) during cycle ergometer exercise. Methods: The groups were submitted to a working memory test, a short memory test and a semantic memory test, before and during a 20-minute cycle ergometer exercise at 80% of their age-predicted maximal heart rate. Results: Significant differences (p=0.04) were observed in scores on the digit backward test during exercise when young individuals were compared to healthy older adults. This result indicates that young subjects, as expected, had better performance than elderly. No significant differences were found among the groups for the digit forward subtest (p=0.40) or the vocabulary test (p=0.69). Conclusion: Data from this study showed that healthy older adults had impaired performance on higher cognitive tasks when these assignments were applied together with motor tasks.

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Falls Risk and Simulated Driving Performance in Older Adults

Journal of Aging Research ◽

10.1155/2013/356948 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 9

Author(s):

John G. Gaspar ◽

Mark B. Neider ◽

Arthur F. Kramer

Keyword(s):

Older Adults ◽

Task Performance ◽

Dual Task ◽

Response Times ◽

Cognitive Task ◽

Driving Performance ◽

Unexpected Events ◽

Falls Risk ◽

Simulated Driving ◽

Dual Task Performance

Declines in executive function and dual-task performance have been related to falls in older adults, and recent research suggests that older adults at risk for falls also show impairments on real-world tasks, such as crossing a street. The present study examined whether falls risk was associated with driving performance in a high-fidelity simulator. Participants were classified as high or low falls risk using the Physiological Profile Assessment and completed a number of challenging simulated driving assessments in which they responded quickly to unexpected events. High falls risk drivers had slower response times (~2.1 seconds) to unexpected events compared to low falls risk drivers (~1.7 seconds). Furthermore, when asked to perform a concurrent cognitive task while driving, high falls risk drivers showed greater costs to secondary task performance than did low falls risk drivers, and low falls risk older adults also outperformed high falls risk older adults on a computer-based measure of dual-task performance. Our results suggest that attentional differences between high and low falls risk older adults extend to simulated driving performance.

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Transcranial Direct Current Stimulation May Improve Cognitive-Motor Function in Functionally Limited Older Adults

Neurorehabilitation and Neural Repair ◽

10.1177/1545968318792616 ◽

2018 ◽

Vol 32 (9) ◽

pp. 788-798 ◽

Cited By ~ 15

Author(s):

Brad Manor ◽

Junhong Zhou ◽

Rachel Harrison ◽

On-Yee Lo ◽

Thomas G. Travison ◽

...

Keyword(s):

Older Adults ◽

Prefrontal Cortex ◽

Executive Function ◽

Direct Current ◽

Dual Task ◽

Transcranial Direct Current Stimulation ◽

Dorsolateral Prefrontal Cortex ◽

Dual Tasking ◽

Direct Current Stimulation ◽

Dorsolateral Prefrontal

Objective. To determine the effects of a transcranial direct current stimulation (tDCS) intervention with the anode placed over the left dorsolateral prefrontal cortex (dlPFC) and cathode over the right supraorbital region, on cognition, mobility, and “dual-task” standing and walking in older adults with mild-to-moderate motor and cognitive impairments. Methods. A double-blinded, block-randomized, sham-controlled trial was conducted in 18 nondemented, ambulatory adults aged ⩾65 years with slow walking speed (⩽1.0 m/s) and “executive” dysfunction (Trail Making Test B score ⩽25th percentile of age- and education-matched norms). Interventions included ten 20-minute sessions of tDCS or sham stimulation. Cognition, mobility, and dual-task standing and walking were assessed at baseline, postintervention, and 2 weeks thereafter. Dual tasking was also assessed immediately before and after the first tDCS session. Results. Intervention compliance was high (mean ± SD = 9.5 ± 1.1 sessions) and no unexpected or serious side effects were reported. tDCS, compared with sham, induced improvements in the Montreal Cognitive Assessment total score ( P = .03) and specifically within the executive function subscore of this test ( P = .002), and in several metrics of dual-task standing and walking ( P < .05). Each of these effects persisted for 2 weeks. tDCS had no effect on the Timed Up-and-Go test of mobility or the Geriatric Depression Scale. Those participants who exhibited larger improvements in dual-task standing posture following the first tDCS session exhibited larger cognitive-motor improvements following 2 weeks of tDCS ( P < .04). Interpretation. tDCS intervention designed to stimulate the left dorsolateral prefrontal cortex may improve executive function and dual tasking in older adults with functional limitations.

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Neuroimaging, Behavioral, and Gait Correlates of Fall Profile in Older Adults

Frontiers in Aging Neuroscience ◽

10.3389/fnagi.2021.630049 ◽

2021 ◽

Vol 13 ◽

Author(s):

Krystal M. Kirby ◽

Sreekrishna Pillai ◽

Robert M. Brouillette ◽

Jeffrey N. Keller ◽

Alyssa N. De Vito ◽

...

Keyword(s):

Older Adults ◽

Task Performance ◽

Dual Task ◽

Cognitive Task ◽

Community Dwelling ◽

Finger Tapping ◽

Task Condition ◽

Dual Task Condition ◽

Brain Functioning ◽

Dual Task Performance

Prior research has suggested that measurements of brain functioning and performance on dual tasks (tasks which require simultaneous performance) are promising candidate predictors of fall risk among older adults. However, no prior study has investigated whether brain function measurements during dual task performance could improve prediction of fall risks and whether the type of subtasks used in the dual task paradigm affects the strength of the association between fall characteristics and dual task performance. In this study, 31 cognitively normal, community-dwelling older adults provided a self-reported fall profile (number of falls and fear of falling), completed a gait dual task (spell a word backward while walking on a GaitRite mat), and completed a supine dual task (rhythmic finger tapping with one hand while completing the AX continuous performance task (AX-CPT) with the other hand) during functional magnetic resonance imaging (fMRI). Gait performance, AX-CPT reaction time and accuracy, finger tapping cadence, and brain functioning in finger-tapping-related and AX-CPT-related brain regions all showed declines in the dual task condition compared to the single task condition. Dual-task gait, AX-CPT and finger tapping performance, and brain functioning were all independent predictors of fall profile. No particular measurement domain stood out as being the most strongly associated measure with fall variables. Fall characteristics are determined by multiple factors; brain functioning, motor task, and cognitive task performance in challenging dual-task conditions all contribute to the risk of falling.

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