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Fr-009-Orthostatic Hypotension in Parkinson’s Disease is Associated with Lower Neural Efficiency During Verbal Letter Fluency Testing While Upright: An fNIRS Study
In Parkinson’s disease (PD) orthostatic hypotension (OH) is associated with cognitive impairment. This study aimed to determine positional differences in cognitive performance and cerebral hemodynamics in PD with and without OH, since OH could be a treatable risk factor for cognitive dysfunction. Participants with PD with OH (n=4) and without OH (n=8) underwent repeated cognitive testing in supine/sitting and upright positions while wearing a functional near infrared spectroscopy (fNIRS) sensor. The group with OH had low neural efficiency during the verbal letter fluency test while upright, supporting the hypothesis that impaired cerebral hemodynamic regulation contributes to cognitive impairment. Continue reading
Fr-006-The Utility of fNIRS for Evaluating Human Voice Acoustics for Stress Management
This study examined the utility of fNIRS in assessing soothing-voice-facilitated mental stress recovery. For this purpose, we measured the prefrontal cortex activity of 35 participants during a stress task and its recovery phase. We used a soothing voice intervention during experimental group recovery. Two control groups received a flat, robotic voice or silence to distinguish the effects of voice stimulation from attention shifts to irrelevant sounds. Measurements of fNIRS and salivary cortisol showed that stress markers dropped faster in the presence of a natural, soothing voice compared to both controls. Continue reading
Fr-003-Sensorimotor neural activity during postural control in concussed individuals
This study examined sensorimotor activation during postural control after sport related concussion. 44 concussed athletes (with and without post-concussion symptoms) and 22 non-concussed athletes participated in the study. Sensorimotor activation was measured during postural control conditions with eyes opened/closed and/or un/stable ground. Symptomatic concussed athletes were characterized by decreased balance and increased brain activation in the Post Central Gyrus, Superior Parietal Lobe, and Supramarginal Gyrus during eyes closed and on unstable surface conditions, when compared to asymptomatic and non-concussed participants. Therefore, increased sensorimotor neural activity cannot compensate for impaired postural control functions in concussed and symptomatic athletes. Continue reading
Fr-027-Evaluating Statistical Learning with Qualitative Regressors: A GLM Methodology for HD-DOT Data
The brain uses environmental sensory inputs to make predictions about future events, a process known as statistical learning. Since prediction confidence is a measure of the likelihood of prediction accuracy, it may modulate the brain’s response to prediction-making. To explore this, we collected high-density diffuse optical tomography data from twenty participants tasked with playing a stock market prediction game. A general linear model was used to fit a linear combination of haemodynamic and qualitative regressors to the task-related responses. Preliminary results suggest that both prediction error and confidence regressors modulate prefrontal cortex activity differently. Continue reading
Vi-026-Changes in Cerebral Haemodynamic Responses During a Sustained Attention Task Following Exertional Hyperthermia
The effects of exertional hyperthermia on neural responses and sustained attention remains equivocal. We evaluated the continuous changes in cerebral haemodynamic responses in bilateral dorsolateral prefrontal cortices during a sustained attention task at the start and end of exercise under heat stress. Exertional hyperthermia under warm environmental conditions resulted in decreased cerebral blood volume and higher error rate compared with cool environmental conditions. Findings suggest potential associations between alterations in cerebral haemodynamic responses and impairments in sustained attention during exercise in the heat. Continue reading
Vi-001-Investigating Motor Imagery with fNIRS-BCI in Lower Limb Movements
This study investigates the utility of functional near-infrared spectroscopy (fNIRS) for detecting cortical brain activity during motor imagery tasks. Ten participants performed knee flexion and extension imagery tasks while multi-channel continuous wave fNIRS system records the signals from the motor cortex. Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM) algorithms were employed to classify the data for fNIRS-BCI applications. SVM outperformed LDA, achieving accuracies of 88.8% and 89.4% for two-feature and three-feature combinations. Increased activation was observed in brain maps during knee flexion imagery. Continue reading
Fr-018-Evaluating Cortical Activity and Balance Performance in Alpine Skiers
The study evaluates the balance performance of young skiers using single-leg stance (SLS) and dual-leg stance (DLS) by measuring cortical activation using fNIRS and modified hope balance test (MHBT). A statistical framework Functional mix effect model was used to model the difference between right-leg stance (RLS), left-leg stance (LLS), and DLS. The results show a significant difference (P<0.0001) in motor cortex hemodynamics during SLS and DLS while no significant difference was found during RLS and LLS. The study also contrasts Broca regions' responses to various tasks. These findings contribute to understanding the neural mechanisms governing balance control in skiers. Continue reading
Fr-043-Prefrontal cortical activations when learning irregular features in words and person
Every word and person are unique, often displaying features that differ from the majority of others (irregular features). Learning irregular features is crucial but challenging. Inhibition, supported by the prefrontal cortex, is important for such learning in words (Qiu et al., 2023). However, it is unclear whether same prefrontal regions support irregularity learning across domains (word, person). Our study involves 35 adults learning regular and irregular features in words and person across five sessions, with fNIRS recording prefrontal cortical activations. Analyses will uncover neural substrates of irregularity learning in word and person domains, and how the activations change over sessions. Continue reading
Fr-052-Quantifying cerebral metabolic and microvascular parameters during and after the cardiac arrest
Cardiac arrest (CA) is a massive and terrifying health problem. Minimizing the effects of CA on the brain requires quantitative real-time bedside monitoring of the cerebral status. We apply a coherent hemodynamic spectroscopy model to cerebral hemodynamic data from a pig model of the cardiac arrest, which allows for recovering various microvascular and metabolic parameters of the brain. This provides valuable knowledge of the impact of CA on the brain and ways to improve treatment. In the future our approach may lead to a clinical non-invasive technique for measuring microvascular and metabolic parameters in CA patients. Continue reading
Fr-051-Frontoparietal network connectivity among preschool-aged offspring at familial risk for ADHD
Aberrant connectivity in the frontoparietal network (FPN) of preschool-aged children may precede ADHD symptoms and serve as early markers of risk for the development of childhood ADHD. FPN connectivity was assessed, using fNIRS, among 4- and 5-year-old children at high and low familial risk for ADHD. Increased connectivity between the prefrontal cortex and posterior parietal appears to be necessary to sustained attention for young children likely to develop ADHD. Continue reading