Distinct fNIRS-Derived HbO2 Trajectories During the Course and Over Repeated Walking Trials Under Single- and Dual-Task Conditions: Implications for Within Session Learning and Prefrontal Cortex Efficiency in Older Adults

Abstract Background Neural trajectories of gait are not well established. We determined two distinct, clinically relevant neural trajectories, operationalized via functional near-infrared spectroscopy (fNIRS) HbO2 measures in the prefrontal cortex (PFC), under Single-Task-Walk (STW), and Dual-Task-Walk (DTW) conditions. Course trajectory assessed neural activity associated with attention during the course of a walking task; the second trajectory assessed neural activity associated with learning over repeated walking trials. Improved neural efficiency was defined as reduced PFC HbO2 after practice. Methods Walking was assessed under STW and DTW conditions. fNIRS was utilized to quantify HbO2 in the PFC while walking. Burst measurement included three repeated trials for each experimental condition. The course of each walking task consisted of six consecutive segments. Results Eighty-three nondemented participants (mean age = 78.05 ± 6.37 years; %female = 49.5) were included. Stride velocity (estimate = −0.5259 cm/s, p = <.0001) and the rate of correct letter generation (log estimate of rate ratio = −0.0377, p < .0001) declined during the course of DTW. In contrast, stride velocity (estimate = 1.4577 cm/s, p < .0001) and the rate of correct letter generation (log estimate of rate ratio = 0.0578, p < .0001) improved over repeated DTW trials. Course and trial effects were not significant in STW. HbO2 increased during the course of DTW (estimate = 0.0454 μM, p < .0001) but declined over repeated trials (estimate = −0.1786 μM, p < .0001). HbO2 declined during the course of STW (estimate = −.0542 μM, p < .0001) but did not change significantly over repeated trials. Conclusion We provided evidence for distinct attention (course) and learning (repeated trials) trajectories and their corresponding PFC activity. Findings suggest that learning and improved PFC efficiency were demonstrated in one experimental session involving repeated DTW trials.

Download Full-text

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

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acab062.27 ◽

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.

Download Full-text

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

Sensors ◽

10.3390/s21186159 ◽

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.

Download Full-text

Reforming Sectarian Beliefs in Iraq: Winning the Peace

Communication Society and Media ◽

10.22158/csm.v4n1p8 ◽

2021 ◽

Vol 4 (1) ◽

pp. p8

Author(s):

Michael Oler ◽

Anthony Johnson ◽

Anna McCulloh ◽

Munqith Dagher ◽

Anita Day ◽

...

Keyword(s):

Prefrontal Cortex ◽

Neural Activity ◽

Public Perception ◽

Near Infrared ◽

Brain Regions ◽

Frontal Pole ◽

Functional Near Infrared Spectroscopy ◽

Imaging Device ◽

Neural Imaging ◽

The Right

Sectarian violence continues in Iraq affecting regional and world security. Neuroscience techniques are used to assess the mentalizing process and counter-arguing in response to videos designed to prevent extremist radicalization. Measurement of neural activity in brain Regions of Interest (ROI) assists identification of messages which can promote favorable behavior. Activation of the Medial Prefrontal Cortex (MPFC) is associated with message adoption and behavior change. Public Service Announcements (PSAs) have not been effective in reducing violence in Iraq. This study demonstrates that the four PSAs investigated in this study do not activate the MPFC. The RLPFC is a brain ROI associated with counter-arguing and message resistance. This study demonstrates that reduction in activity in the Right Lateral Prefrontal Cortex (RLPFC) is associated with decreased sectarianism. Engagement was measured and is associated with activity in the frontal pole regions.We introduce Functional Near-infrared Spectroscopy (fNIRS) to measure the neural activity of highly sectarian Iraqis in response to these anti-sectarian messages. Neural activity was measured while viewing three PSAs and a fourth unpublished video. All four videos are intended to reduce sectarianism. A novel sectarianism scale is introduced to measure sectarian beliefs before and after the messages. This sectarian scale has high internal consistency as measured by Cronbach’s alpha. Measured activation of brain ROIs are correlated with changes in the sectarian scale. Twelve Sunni and twelve Shi’a Iraqis participated in the study. Subjects were shown the four videos in randomized order, while equipped with a fNIRS neural imaging device. All four videos produced significant engagement. None of the videos reduced sectarianism nor caused brain activation of adoption. This is consistent with the widely held Iraqi public perception that the PSAs are ineffective. Only one video, which was un-published, caused reduced sectarian beliefs. This un-published fourth video was associated with decreased counter-arguing. Counter-arguing is associated with message resistance.

Download Full-text

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

Innovation in Aging ◽

10.1093/geroni/igab046.616 ◽

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.

Download Full-text

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

Age and Ageing ◽

10.1093/ageing/afz164.36 ◽

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.

Download Full-text

Prefrontal activation related to spontaneous creativity with rock music improvisation: A functional near-infrared spectroscopy study

Scientific Reports ◽

10.1038/s41598-019-52348-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Atsumichi Tachibana ◽

J. Adam Noah ◽

Yumie Ono ◽

Daisuke Taguchi ◽

Shuichi Ueda

Keyword(s):

Prefrontal Cortex ◽

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Neural Activity ◽

Rock Music ◽

Near Infrared ◽

Brain Activity ◽

Functional Near Infrared Spectroscopy ◽

Left Dlpfc ◽

Dorsolateral Prefrontal

Abstract Understanding how the brain modulates improvisation has been the focus of numerous studies in recent years. Models have suggested regulation of activity between default mode and executive control networks play a role in improvisational execution. Several studies comparing formulaic to improvised sequences support this framework and document increases in activity in medial frontal lobe with decreased activity in the dorsolateral prefrontal cortex (DLPFC). These patterns can be influenced through training and neural responses may differ between in beginner and expert musicians. Our goal was to test the generalizability of this framework and determine similarity in neural activity in the prefrontal cortex during improvisation. Twenty guitarists performed improvised and formulaic sequences in a blues rock format while brain activity was recorded using functional near-infrared spectroscopy. Results indicate similar modulation in DLPFC as seen previously. Specific decreases of activity from left DLPFC in the end compared to beginning or middle of improvised sequences were also found. Despite the range of skills of participants, we also found significant correlation between subjective feelings of improvisational performance and modulation in left DLPFC. Processing of subjective feelings regardless of skill may contribute to neural modulation and may be a factor in understanding neural activity during improvisation.

Download Full-text

Mild Cognitive Impairments Attenuate Prefrontal Cortex Activations during Walking in Older Adults

Brain Sciences ◽

10.3390/brainsci10070415 ◽

2020 ◽

Vol 10 (7) ◽

pp. 415 ◽

Cited By ~ 1

Author(s):

Roee Holtzer ◽

Meltem Izzetoglu

Keyword(s):

Prefrontal Cortex ◽

Dual Task ◽

Near Infrared ◽

Cognitive Impairments ◽

Cortical Control ◽

Cognitive Interference ◽

Functional Near Infrared Spectroscopy ◽

Activation Patterns ◽

Opposite Trend ◽

Healthy Control

The presence of Mild Cognitive Impairments (MCI) is associated with worse gait performance. However, the effect of MCI on cortical control of gait, as assessed during active walking, is unknown. We hypothesized that MCI would be associated with attenuated activations and limited improvement in efficiency in the Prefrontal cortex (PFC) under cognitively-demanding walking conditions. Functional Near-Infrared Spectroscopy (fNIRS) was used to assess Oxygenated Hemoglobin (HbO2) in the PFC during Single-Task-Walk (STW), cognitive interference (Alpha) and Dual-Task-Walk (DTW) conditions. Three repeated trials in each experimental condition were administered. Healthy control (n = 71; mean age = 76.82 ± 6.21 years; %female = 50.7) and MCI (n = 11; mean age = 78.27 ± 4.31 years; %female = 45.5) participants were included. The increase in HbO2 from STW to DTW was attenuated among MCI participants compared to controls (estimate = 0.505; p = 0.001). Whereas, among controls, HbO2 increased from Alpha to DTW, the opposite was observed among MCI participants (estimate = 0.903; p < 0.001). In DTW, the decline in HbO2 from trial 1 to 2 was attenuated in MCI participants compared to controls (estimate = 0.397; p = 0.008). Moreover, whereas HbO2 declined from trial 1 to 3 among controls, MCI participants showed the opposite trend (estimate = 0.946; p < 0.001). MCI was associated with attenuated brain activation patterns and compromised ability to improve PFC efficiency during dual-task walking.

Download Full-text

Using Functional Near Infrared Spectroscopy to Assess Cognitive Workload

Defence Life Science Journal ◽

10.14429/dlsj.6.15616 ◽

2021 ◽

Vol 6 (3) ◽

pp. 197-204

Author(s):

D Ravi ◽

K. Ramachandran ◽

Pushpendra Kumar Singh ◽

Mistu Mahajabin

Keyword(s):

Prefrontal Cortex ◽

Cognitive Load ◽

Human Performance ◽

Near Infrared ◽

Mental Workload ◽

Binary Logistic Regression ◽

Repeated Measure ◽

Binary Logistic Regression Model ◽

Functional Near Infrared Spectroscopy ◽

Task Conditions

Quantification of mental workload is a significant aspect of monitoring and adaptive aiding systems that are intended to improve the efficiency and safety of human–machine systems. Functional near Infrared (fNIR) spectroscopy is a field-deployable brain monitoring device that provides a measures of cerebral hemodynamic within the prefrontal cortex. The purpose of this study was to assess the cognitive load by using Performance (reaction time), Behavioral metrics (NASA TLX) and Neuro-Cognitive Measures (Hemodynamic response). To observe the activation in prefrontal cortex, we employed Functional Near Infrared (fNIR) Spectroscopy with a Standard Stroop task. A total of 25 healthy participants (N 18 Male and N 07 Female, M Age 25.5 SD 7.6), participated in the study. For statistical analysis, a repeated measure t-test was computed to compare the Oxy (Δ[HbO2]) and De-Oxy (Δ[hHb]) changes under Congruent and In-Congruent task conditions. For Classification, Binary logistic regression model applied to identify how accurately classifying the varied workload conditions. The finding shows that fNIR measures had adequate predictive power for estimating task performance in workload conditions. In this paper, we have found evidence that fNIR can be used as indicator of cognitive load which is important for optimal human performance.

Download Full-text

A Functional Near-Infrared Spectroscopy Study on the Cortical Haemodynamic Responses During the Maastricht Acute Stress Test

Scientific Reports ◽

10.1038/s41598-019-49826-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

N. K. Schaal ◽

P. Hepp ◽

A. Schweda ◽

O. T. Wolf ◽

C. Krampe

Keyword(s):

Prefrontal Cortex ◽

Infrared Spectroscopy ◽

Near Infrared Spectroscopy ◽

Stress Responses ◽

Neural Activity ◽

Near Infrared ◽

Acute Stress ◽

Stress Test ◽

Brain Regions ◽

Functional Near Infrared Spectroscopy

Abstract In order to better understand stress responses, neuroimaging studies have investigated the underlying neural correlates of stress. Amongst other brain regions, they highlight the involvement of the prefrontal cortex. The aim of the present study was to explore haemodynamic changes in the prefrontal cortex during the Maastricht Acute Stress Test (MAST) using mobile functional Near-Infrared Spectroscopy (fNIRS), examining the stress response in an ecological environment. The MAST includes a challenging mental arithmic task and a physically stressful ice-water task. In a between-subject design, participants either performed the MAST or a non-stress control condition. FNIRS data were recorded throughout the test. Additionally, subjective stress ratings, heart rate and salivary cortisol were evaluated, confirming a successful stress induction. The fNIRS data indicated significantly increased neural activity of brain regions of the dorsolateral prefrontal cortex (dlPFC) and the orbitofrontal cortex (OFC) in response to the MAST, compared to the control condition. Furthermore, the mental arithmetic task indicated an increase in neural activity in brain regions of the dlPFC and OFC; whereas the physically stressful hand immersion task indicated a lateral decrease of neural activity in the left dlPFC. The study highlights the potential use of mobile fNIRS in clinical and applied (stress) research.

Download Full-text

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

Neurorehabilitation and Neural Repair ◽

10.1177/1545968320924430 ◽

2020 ◽

Vol 34 (7) ◽

pp. 589-599 ◽

Cited By ~ 5

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.

Download Full-text