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Fr-013-Investigating the Neural Bases of Language Processing During a Live Social Interaction: A fNIRS Study of Neurotypical and Autistic Children
The present study examined the neural bases of language processing during a live social interaction in 20 neurotypical (NT) and 20 autistic (ASD) children, 3 to 6 years old. fNIRS was used to measure children’s brain response during a live language condition (listened to story read by live experimenter) and a recorded language condition (listened to story played via audio recording). We found group differences in brain response to live language and recorded language, as well as associations between children’s brain response and their language skills. Findings may help to explain why ASD children experience challenges using and understanding language. Continue reading
Fr-011-The association between caregiver inhibitory control, caregiving behaviours, and infant visual cognition
This study investigated whether caregiver inhibitory control was associated with infant visual cognition and whether caregiver behaviours during dyadic interactions could explain this association. Caregiver inhibitory control was assessed using a Go-NoGo task and infant visual cognition was assessed using a preferential looking task. Caregiver behaviours were coded from naturalistic play interactions. Better caregiver inhibitory control was associated with lesser left middle frontal gyrus (lMFG) activation in infants. While caregiver behaviours did not mediate this association, better caregiver scaffolding was negatively associated with lesser infant lMFG activation, suggesting that supportive caregiving might directly impact attentional control networks in infants. Continue reading
Vi-025-Imaging static absorbing properties using wavelength modulated near-infrared spectroscopy
A method called wavelength-modulated near-infrared spectroscopy is used to estimate the absolute concentrations of absorbers in highly scattering media using measurements of the rate of change of optical attenuation with wavelength. The method is demonstrated using three experimental systems based on a wavelength-modulated source, a spectrometer, and discrete sources at adjacent wavelengths. Measurements are independent of absolute intensity and thus less influenced by changes in coupling (to which hair is a significant contributor) which cause artefacts in conventional NIRS data. Images of a tissue equivalent phantom clearly reveal internal absorbers despite a random layer of dark hair on the surface. Continue reading
Fr-008-fNIRS Evaluation of Cortical Reorganization Following Brief Speech-in-Noise Training
This study investigates cortical effects of single-session speech-in-noise (SIN) training using fNIRS and assesses data reproducibility. Thirty normal-hearing participants underwent SIN training with noise-vocoded stimuli. Significant post-training SIN enhancements were found, particularly in those with poorer initial performance or lower pre-training activation in the left middle temporal gyrus (MTG). MTG activation to trained stimuli decreased post-training, suggesting improved neural processing efficiency. Group-level reliability was confirmed, but individual-level reproducibility of fNIRS data was poor. These findings underscore the significance of fNIRS in elucidating the mechanisms driving auditory learning and plasticity yet highlight the challenges in translating fNIRS data to clinical practice. Continue reading
Fr-005-Repetitive head impacts in Para sports alter brain oxygenation patterns
Para swimmers with limb deficiency are faced with the situation that they must use their head to finish each competition by a hit to the wall. Repetitive head impacts may impair behavioral and brain functions. We therefore investigated neurobehavioral functions of a Para swimmer with dysmelia before and after repetitive head impacts (T1) and without (T2). Behavioral and brain functions decreased from pre to post at T1 but not at T2. Para swimmers with limb deficiency are therefore affected from similar consequences onto brain health that are observed after repeated sport-related concussions. Continue reading
Fr-004-Investigating Parkinson’s Disease Motor Cortex Functional Connectivity with fNIRS
We employed fNIRS to examine motor cortex functional connectivity in Parkinson's Disease (PD), comparing it with controls using graph theoretical network analysis and network-based statistics. We found PD patients have significantly lower clustering coefficients and small-world indices over a wide range of sparsity thresholds, indicating a less efficient motor network, supported by network-based statistics showing a disconnected bilateral subnetwork. These findings underscore the potential of fNIRS in understanding PD neural basis, highlighting significant alterations in motor cortex connectivity and organization, and suggesting a path for future research into the condition's neurological underpinnings Continue reading
Fr-002-Neurological Impacts of Yoga Asana: An fNIRS study
The practice of Yoga Asana has been observed to relieve symptoms associated with anxiety and depression and this study offers neurological insight into these psychological improvements. Applying functional near-infrared spectroscopy (fNIRS) changes in prefrontal cortex (PFC) activity of 27 healthy adults during and after executing 4 Yoga Asanas for 23 minutes was measured. Results demonstrated all Asanas significantly increased PFC activity particularly in the right hemisphere whereas analysis of resting state functional connectivity post-yoga practice showed a significant decrease mainly in the left PFC amongst network connections previously established as being hyperactive in patients suffering from mood disorders. Continue reading
Fr-032-Cross-modal functional plasticity after cochlear-implantation
We investigated task-induced cross-modal functional connectivity (CMFC) between visual and auditory cortices in cochlear implant (CI) users and its correlation with speech performance outcomes using fNIRS. Brain imaging was conducted in one month and one-year post-CI on 22 recipients and on 17 normal-hearing subjects, including resting state and task-based experiments. Significant correlations were observed between average contra-lateral CMFC and CI speech outcomes, particularly in angular gyrus links. Task-induced CMFC was significantly higher in CI users compared to NH subjects, indicating stronger reliance on cross-modal activities post-implantation. Proximity of the auditory cortex to the visual cortex significantly contributes to post-CI CMFC. Continue reading
Fr-026-Real-time inference of molecular composition from broadband spectroscopy of brain tissue
We analyze a technique for fast and accurate inference of changes in the molecular composition of brain tissue from broadband NIRS and HSI monitoring. The method is based on the Beer-Lambert law to analytically connect the spectra with concentrations and utilizes deep learning to speed up the concentration inference compared to traditional optimization means. The results reveal a sub-second molecular composition inference and a possibility of contrasting semantically different physiological parts. Continue reading
Fr-040-A transportable hyperspectral imaging setup based on fast, high-density spectral scanning for in situ quantitative biochemical mapping of fresh tissue biopsies
We present here a transportable, high-density, hyperspectral imaging setup, named HyperProbe1, to provide in situ, fast biochemical analysis of fresh surgical samples, within 1 hour after excision. The system is applied on ex vivo biopsies of glioma from routine patients, including different tumour gradings. Quantitative analysis of the composition of the tissue is performed via fast spectral unmixing to map biomarkers, such as oxy- and deoxyhaemoglobin, cytochrome-c-oxidase and lipid content. The versatility of HyperProbe1 can enable its utilisation as investigative tool to provide tailored HSI technology, that could be translated into the clinics as compact, cost-effective prototypes for intraoperative neuronavigation. Continue reading