A-9 Examining Neural Variability during Dual-Task Walking and Cortical Thickness in Older Adults

2021 ◽  
Vol 36 (6) ◽  
pp. 1048-1048
Author(s):  
Daliah Ross ◽  
Mark E Wagshul ◽  
Meltem Izzetoglu ◽  
Roee Holtzer
Keyword(s):  
Older Adults ◽  
Prefrontal Cortex ◽  
Cortical Thickness ◽  
Dual Task ◽  
Near Infrared ◽  
Adverse Outcomes ◽  
Functional Near Infrared Spectroscopy ◽  
Single Task ◽  
Mobility Impairments ◽  
Neural Variability

Abstract Objective Greater intraindividual variability (IIV) in behavioral and cognitive performance is a risk factor for adverse outcomes but research concerning IIV in neural signal is scarce. Using functional near-infrared spectroscopy (fNIRS), we showed that IIV in oxygenated hemoglobin (HbO2) levels in the prefrontal cortex increased from single task (Single-Task-Walk–STW; Single-Task-Alpha–STA) to Dual-Task-Walk (DTW) conditions in older adults. Herein, we predicted that, consistent with the neural inefficiency hypothesis, reduced cortical thickness would be associated with greater increases in IIV in fNIRS-derived HbO2 from single tasks to DTW when adjusting for behavioral performance. Method Participants were right-handed older adults without dementia recruited from the community (N = 55; M(SD) age = 74.84(4.97); %female = 49.1). Neuroimaging included fNIRS for HbO2 levels in the prefrontal cortex during tasks and MRI for cortical thickness. IIV was operationalized using the SD of fNIRS-derived HbO2 observations assessed during a 30-s interval in each experimental condition. Results Moderation analyses, assessed through linear mixed effects models, revealed that in several frontal (p < 0.02), parietal (p < 0.02), temporal (p < 0.01), and occipital (p < 0.01) regions, thinner cortex was associated with greater increases in HbO2 IIV from the single tasks to DTW. Conclusion Reduced cortical thickness was associated with inefficient increases in IIV in fNIRS-derived HbO2 from single tasks to dual-task walking. Worse IIV in gait performance under DTW predicts adverse mobility outcomes. Reduced cortical thickness and worse IIV of fNIRS-derived HbO2 during DTW are possible brain mechanisms that explain the risk of developing mobility impairments in aging and disease populations.

scholarly journals PREFRONTAL CORTICAL ACTIVITY DIFFERENCES WHILE DUAL-TASK WALKING IN OLDER ADULTS WITH IMPAIRED MOBILITY

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S793-S794
Author(s):  
Manuel E Hernandez
Keyword(s):  
Older Adults ◽  
Dual Task ◽  
Near Infrared ◽  
Local Community ◽  
Cognitive Task ◽  
Mobility Impairment ◽  
Functional Near Infrared Spectroscopy ◽  
Mobility Impairments ◽  
Prefrontal Cortical ◽  
Walking Difficulty

Abstract Mobility impairments are prevalent in older adults. Whereas walking had traditionally been viewed as an autonomous process, evidence over the last decade has shown that cognitive processes such as attention and executive function have a significant impact on gait function in older adults. However, the exact neural mechanisms underlying difficulties in the control of mobility in older adults remains an open question. We examine the changes in the executive control of mobility in older adults with mobility impairments using functional near-infrared spectroscopy, as operationalized by performance in the community balance and mobility scale (CB&M). We hypothesized that prefrontal cortical (PFC) activity increases would be higher in older adults with mobility impairments, compared with older adults without mobility impairment, as dual-task walking difficulty increased. Older adults with (n=10, mean±SD age: 77±8 years, 8 females, CB&M= 58±12) and without mobility impairment (n=14, mean±SD age: 63±9 years, 11 females, CB&M= 87±6) were recruited from the local community. Dual-task walking was performed at a comfortable pace, while the difficulty of the concurrent cognitive task was increased using the modified Stroop test. PFC activity was measured using measures of oxygenated hemoglobin across the PFC. Older adults with mobility impairments demonstrated disproportionate increases in PFC activity, in comparison to those without mobility impairments, as the difficulty of the concurrent cognitive task increased (P<.001), even after controlling for age. In conclusion, these data suggest that older adults with mobility impairments may require greater attentional resources than those without mobility impairments when concurrently performing thinking and walking tasks.

scholarly journals 36 Altered Prefrontal Cortex Responses in Older Adults with Subjective Memory Complaints and Dementia During Dual-Task Gait: An Fnirs Study

2019 ◽  
Vol 48 (Supplement_4) ◽  
pp. iv9-iv12
Author(s):  
Wei-Peng Teo ◽  
Timo Rantalainen ◽  
Helen Macpherson
Keyword(s):  
Older Adults ◽  
Prefrontal Cortex ◽  
Dual Task ◽  
Near Infrared ◽  
Single Channel ◽  
Subjective Memory Complaints ◽  
Medical Systems ◽  
Subjective Memory ◽  
Functional Near Infrared Spectroscopy ◽  
Memory Complaints

Abstract In this study, we investigated the effects of walking during single-task and dual-task gait (STG and DTG) conditions, on left prefrontal cortex (LPFC) activation in older adults with subjective memory complaints (SMC) and Dementia. A total of 72 older adults (aged 65-94 yrs; 33 Healthy; 28 SMC; 11 Dementia) were recruited from the community and assisted living facilities. A portable 7m zeno walkway gait analysis mat was used to measure stride, velocity, length and duration during 4 passes of STG and DTG each. A portable single-channel functional near-infrared spectroscopy (fNIRS) device (Portalite, Artinis Medical Systems) was placed over the LPFC to measure changes in oxyhaemoglobin response (O2Hb) during STG and DTG. One-way analysis of variance (ANOVA) with bonferroni post-hoc t-test for multiple comparisons was used to determine differences between groups. Our results showed that stride velocity, duration and length during STG (all p<0.05) and DTG (all p<0.000) were significantly impaired in the Dementia group compared to Healthy and SMC groups, while no significant differences were observed between Healthy and SMC groups. For STG, a greater increase in O2Hb (p<0.05) was observed in the Dementia group compared to the Healthy and SMC groups, while no differences were observed between Healthy and SMC. However, a significant increase and decline in O2Hb was observed during DTG in the SMC and Dementia groups respectively, compared to Healthy. Our findings indicate an altered pattern of cerebral haemodynamic response of the PFC in people with SMC and Dementia that may be indicative of cognitive demands of gait. Our findings may have implications for the use of DTG and fNIRS as a potential early biomarker for cognitive declines in older adults.

Cognitive Reserve Moderates the Efficiency of Prefrontal Cortex Activation Patterns of Gait in Older Adults

2021 ◽  
Author(s):  
Roee Holtzer ◽  
Daliah Ross ◽  
Catherine O’Brien ◽  
Meltem Izzetoglu ◽  
Mark E Wagshul
Keyword(s):  
Older Adults ◽  
Prefrontal Cortex ◽  
Dual Task ◽  
Cognitive Functions ◽  
Cognitive Reserve ◽  
Word Reading ◽  
Cognitive Task ◽  
Functional Near Infrared Spectroscopy ◽  
Activation Patterns ◽  
Single Task

Abstract Background Cognitive Reserve (CR) protects against cognitive decline, but whether CR influences the efficiency of cortical control of gait has not been reported. The current study addressed this important gap in the literature. Specifically, we determined the role of CR in moderating the efficiency of functional Near-Infrared-Spectroscopy (fNIRS)-derived HbO2 in the prefrontal cortex (PFC) assessed during active walking. We hypothesized that higher CR would be associated with more efficient brain activation patterns. Methods Participants were 55 (mean age=74.84; %female=49.1) older adults who underwent the combined walking/fNIRS protocol and had MRI data. We used an established dual-task walking paradigm that consisted of three task conditions: Single-Task-Walk (STW), Single-Task-Alpha (STA, cognitive task) and Dual-Task-Walk (DTW). Using the residuals approach, CR was derived from a word-reading test score by removing variance accounted for by socio-demographic variables, tests of current cognitive functions and a measure of structural brain integrity. Results CR moderated the change in fNIRS-derived HbO2 in the PFC across tasks. Higher CR was associated with smaller increases in fNIRS-derived HbO2 from the single tasks to dual task walking (CR x DTW compared to STW: estimate = .183; p < .001; CR x DTW compared to STA: estimate =.257; p < .001). The moderation effect of CR remained significant when adjusting for multiple covariates and concurrent moderation effects of measures of gait performance, current cognitive functions and structural integrity of the brain. Conclusion The current study provided first evidence that higher CR was associated with better neural efficiency of walking in older adults.

scholarly journals Levodopa Facilitates Prefrontal Cortex Activation During Dual Task Walking in Parkinson Disease

2020 ◽  
Vol 34 (7) ◽  
pp. 589-599 ◽  
Author(s):  
Diego Orcioli-Silva ◽  
Rodrigo Vitório ◽  
Priscila Nóbrega-Sousa ◽  
Núbia Ribeiro da Conceição ◽  
Victor Spiandor Beretta ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Parkinson Disease ◽  
Dual Task ◽  
Near Infrared ◽  
Vigilance Task ◽  
Control Group ◽  
Functional Near Infrared Spectroscopy ◽  
Single Task ◽  
Dopaminergic Medication ◽  
Gait Parameters

Background. Although dopaminergic medication improves dual task walking in people with Parkinson disease (PD), the underlying neural mechanisms are not yet fully understood. As prefrontal cognitive resources are involved in dual task walking, evaluation of the prefrontal cortex (PFC) is required. Objective. To investigate the effect of dopaminergic medication on PFC activity and gait parameters during dual task walking in people with PD. Methods. A total of 20 individuals with PD (69.8 ± 5.9 years) and 30 healthy older people (68.0 ± 5.6 years) performed 2 walking conditions: single and dual task (walking while performing a digit vigilance task). A mobile functional near infrared spectroscopy system and an electronic sensor carpet were used to analyze PFC activation and gait parameters, respectively. Relative concentrations of oxygenated hemoglobin (HbO2) from the left and right PFC were measured. Results. People with PD in the off state did not present changes in HbO2 level in the left PFC across walking conditions. In contrast, in the on state, they presented increased HbO2 levels during dual task compared with single task. Regardless of medication state, people with PD presented increased HbO2 levels in the right PFC during dual task walking compared with single task. The control group demonstrated increased PFC activity in both hemispheres during dual task compared with single task. People with PD showed increases in both step length and velocity in the on state compared with the off state. Conclusions. PD limits the activation of the left PFC during dual task walking, and dopaminergic medication facilitates its recruitment.

scholarly journals The Effects of Perceived Pain in the Past Month on Prefrontal Cortex Activation Patterns Assessed During Cognitive and Motor Performances in Older Adults

Pain Medicine ◽  
2020 ◽  
Author(s):  
Hannah Pakray ◽  
Elizabeth Seng ◽  
Meltem Izzetoglu ◽  
Roee Holtzer
Keyword(s):  
Older Adults ◽  
Prefrontal Cortex ◽  
Dual Task ◽  
Near Infrared ◽  
Pain Severity ◽  
Gait Velocity ◽  
Functional Near Infrared Spectroscopy ◽  
Healthy Older Adults ◽  
Perceived Pain ◽  
Subjective Pain

Abstract Objective Pain is prevalent and functionally impactful in older adults. The prefrontal cortex is involved in pain perception, attentional control, and cortical control of locomotion. Although pain is a known moderator of attentional capacity, its moderating effect on cortical control of locomotion has not been assessed. This study aimed to examine the effects of subjective pain on changes in functional near-infrared spectroscopy–derived measurements of oxygenated hemoglobin (HbO2), gait velocity, and cognitive accuracy from single- to dual-task walking conditions among older adults. Subjects The sample consisted of 383 healthy older adults (55% female). Methods Participants completed two single tasks (Single-Task-Walk [STW] and Cognitive Interference [Alpha]) and the Dual-Task-Walk (DTW), during which participants performed the two single tasks simultaneously. The Medical Outcomes Study Pain Severity Scale and Pain Effects Scale were used to assess pain severity and interference. ProtoKinetics Movement Analysis Software was used to assess gait velocity and rate of correct letter generation to assess cognitive accuracy. Functional Near-Infrared Spectroscopy (fNIRS) was used to assess HbO2 during active walking. Results Linear mixed-effects models revealed that HbO2 increased from single- to dual-task conditions. Perceived pain presence was associated with an attenuated increase in HbO2 from Alpha to DTW. Among those with pain, worse pain severity was associated with an attenuated increase in HbO2 from STW to DTW. Pain interference did not moderate the increase in HbO2 from single to dual tasks. Pain did not have a moderating effect on behavioral outcomes. Conclusions Task-related changes in the hemodynamic response in the prefrontal cortex during walking may be a sensitive marker of the effects of subjective pain on brain function in healthy older adults.

scholarly journals Neural Inefficiency During Dual-Task Walking in Older Adults: The Moderating Effect of Brain Morphology

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 288-288
Author(s):  
Daliah Ross ◽  
Mark Wagshul ◽  
Meltem Izzetoglu ◽  
Roee Holtzer
Keyword(s):  
Older Adults ◽  
Cortical Thickness ◽  
Dual Task ◽  
Near Infrared ◽  
Functional Decline ◽  
Brain Regions ◽  
Moderating Effect ◽  
Brain Morphology ◽  
Behavioral Performance ◽  
Functional Near Infrared Spectroscopy

Abstract Aging is accompanied by changes in cognitive, physical, and brain function. Research has found increased activation in the prefrontal cortex (PFC) in dual-task-walk (DTW) as compared to single-task walk (STW) due to increased cognitive demands in the former condition. Older adults have more difficulty with DTW than younger adults, and difficulty with DTW has been found to predict functional decline in aging. As the population gets older, it is important to identify biomarkers predictive of functional decline. The neural inefficiency hypothesis posits that some people, including older adults, utilize more neural resources than others without showing benefits to behavioral performance. We examined the moderating effect of cortical thickness on PFC activation from STW to DTW. We predicted that less cortical thickness would be associated with increased PFC activation but without benefit to behavioral performance, to compensate for limited neural resources. Participants were 55 right-handed community-residing healthy older adults (mean age = 74.84 + 4.97; %female = 49.1). Cortical thickness was measured via MRI. Activation in the PFC was measured via functional near-infrared spectroscopy-derived (fNIRS) oxygenated hemoglobin (HbO2) levels. Analyses controlled for behavioral performance. Linear-mixed-effects models revealed that cortical thickness in several brain regions significantly moderated the increase in HbO2 from STW to DTW, p < 0.01. Thinner cortex, in regions implicated in walking and cognition, was associated with a greater increase in HbO2 levels. Supporting the neural inefficiency hypothesis, results suggest that older adults with greater cortical thinning over-activate the PFC during attention-demanding walking.

scholarly journals Modifications in Prefrontal Cortex Oxygenation in Linear and Curvilinear Dual Task Walking: A Combined fNIRS and IMUs Study

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6159
Author(s):  
Valeria Belluscio ◽  
Gabriele Casti ◽  
Marco Ferrari ◽  
Valentina Quaresima ◽  
Maria Sofia Sappia ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dual Task ◽  
Near Infrared ◽  
Cognitive Task ◽  
Real Life ◽  
Motor Task ◽  
Hemoglobin Concentration ◽  
Cortical Activation ◽  
Functional Near Infrared Spectroscopy ◽  
Gait Quality

Increased oxygenated hemoglobin concentration of the prefrontal cortex (PFC) has been observed during linear walking, particularly when there is a high attention demand on the task, like in dual-task (DT) paradigms. Despite the knowledge that cognitive and motor demands depend on the complexity of the motor task, most studies have only focused on usual walking, while little is known for more challenging tasks, such as curved paths. To explore the relationship between cortical activation and gait biomechanics, 20 healthy young adults were asked to perform linear and curvilinear walking trajectories in single-task and DT conditions. PFC activation was assessed using functional near-infrared spectroscopy, while gait quality with four inertial measurement units. The Figure-of-8-Walk-Test was adopted as the curvilinear trajectory, with the “Serial 7s” test as concurrent cognitive task. Results show that walking along curvilinear trajectories in DT led to increased PFC activation and decreased motor performance. Under DT walking, the neural correlates of executive function and gait control tend to be modified in response to the cognitive resources imposed by the motor task. Being more representative of real-life situations, this approach to curved walking has the potential to reveal crucial information and to improve people’ s balance, safety, and life’s quality.

scholarly journals Motor Skill Training Effect on Real-Time Prefrontal Cortex Activation During Walking

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 162-162
Author(s):  
Subashan Perera ◽  
Theodore Huppert ◽  
Jennifer Brach ◽  
Andrea Rosso ◽  
Nemin Chen
Keyword(s):  
Prefrontal Cortex ◽  
Physical Therapy ◽  
Dual Task ◽  
Motor Skill ◽  
Mixed Models ◽  
Near Infrared ◽  
Skill Training ◽  
Functional Near Infrared Spectroscopy ◽  
Task Time ◽  
Motor Skill Training

Abstract We aimed to test the effects of motor skill training (MST) on gait automaticity measured by changes in prefrontal cortex (PFC) activation during actual walking. We used data from a 12-week trial of older adults (mean age=75.5, 60.5% women) randomized to standard physical therapy and standard+MST in a 1:1 ratio. Functional near infrared spectroscopy (fNIRS) measured PFC activation during simple and dual task walking. We will apply linear mixed models to assess effects of task, time, and MST on PFC activation. We will compare the PFC activation 1) during dual task walking compared to simple walking; 2) across visits after intervention; and 3) between participants receiving MST compared to standard physical therapy. These results will demonstrate whether gait automaticity, as evidenced by PFC activation during walking, is affected by MST.

scholarly journals Effects of fNIRS Processing Methods on Prefrontal Hemodynamics During Single and Dual Task Walking in Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 288-288
Author(s):  
Meltem Izzetoglu ◽  
Roee Holtzer
Keyword(s):  
Older Adults ◽  
Dual Task ◽  
Gold Standard ◽  
Near Infrared ◽  
Strong Support ◽  
Effect Sizes ◽  
Linear Mixed Effect Model ◽  
Artifact Removal ◽  
Functional Near Infrared Spectroscopy ◽  
Mixed Effect

Abstract functional near infrared spectroscopy (fNIRS) has been increasingly used to assess changes in the hemodynamic response during active walking in aging and disease populations. Key findings revealed that HbO2 in the prefrontal cortex (PFC) increased from single-task-walk (STW) to dual-task-walk (DTW) due to the greater cognitive demands inherent in the latter condition. However, previous studies utilized a limited and inconsistent number of algorithms and filters to remove artifacts from fNIRS-derived brain activation data. Critically, there is no gold standard for artifact removal at the present time, which reduces replicability and generalizability. To address this critical limitation, we have reanalyzed a large dataset of older adults (n=83) who underwent our walking protocol by using different hemodynamic conversion parameters (molar extinction coefficients and age and wavelength dependent differential pathlength factors) and applying different filters having various cut-off frequencies for artifact removal. On the extracted hemodynamic responses, namely oxygenated-hemoglobin (HbO2) and deoxygenated-hemoglobin (Hb), linear mixed effect model results indicated that task effects showed similar significant increases in HbO2 from STW to DTW (range of effect sizes was 0.59 to 0.64) and as well as the expected decline in Hb from STW to DTW (range of effect sizes was 0.18 to 0.32) irrespective of the methods used. In addition, the intraclass correlations suggested excellent reliability across methods (HbO2 range = 0.982 to 0.996; Hb range = 0.883 to 0.984). In conclusion, these findings provide strong support to previously published articles but also highlight the need to establish a gold standard for fNIRS processing.

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