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
Fr-035-Subjectivity and Brain Activity-Based Validation to Driving Feedback
In this study, we aim to realize a real-time feedback system that encourages drivers to continuously become aware of safe driving. There are various feedback methods, and so far, five types of subjective impressions have been evaluated using images, warning sounds, and announcements. However, as subjective evaluation alone may lead to responses that intentionally or unintentionally influence the outcome of the experiment, we focused on the brain, which is processing the information, and evaluated feedback by measuring brain activity with NIRS. The results of the experiment indicated that the brain may be activated to process information for those with high subjective evaluation content. Continue reading
Fr-075-Hyperspectral time-resolved near-infrared spectroscopy technique for adult neuromonitoring
Hyperspectral time-resolved near-infrared spectrometers have the potential to monitor adult cerebral blood oxygenation and metabolism with minimal extracerebral contamination; however, they are typically limited by trade-offs between spectral range, spectral resolution, and sampling rate. This work presents a hyperspectral time-resolved near-infrared spectrometer that uses compressive sensing to enable fast data acquisition while maintaining spectral range and resolution. The sensitivity of the device to changes in blood oxygenation and metabolism in deep tissue was confirmed in phantom experiments with comparison to gold standard measures. Future work will validate the sensitivity of the device to adult cerebral blood oxygenation and metabolism. Continue reading
Fr-074-Laughing Together – do people synchronize and bond when they laugh together?
The aim of this study is to investigate if laughing together supports interbrain synchrony which in turn supports positive social outcomes between people. For this purpose, we manipulate laughing in pairs of participants and subsequently measure interbrain synchrony with fNIRS hyperscanning, bonding and joint action. We use a sequential Bayesian approach to achieve the sample size with a Bayes factor of 5 or 1/5. A preliminary Bayes ANOVA (N=84) revealed that the data for the interbrain synchrony are in favor of the null hypotheses. Further variables (laughter, bonding) are currently being analyzed. Data collection is ongoing. Continue reading
Fr-071-Simultaneous broadband NIRS and EEG to characterise social brain specialisation in infants
Our current comprehension of functional specialisation in infants is limited to insights of either spatial or temporal neural activation. We propose that functional specialisation is underpinned by coordinated physiological responses as part of the neurovascular coupling (NVC) pathway. To investigate this, we used broadband NIRS (bNIRS) simultaneously with EEG to measure neural activity alongside haemodynamic and metabolic changes in 4-to-7-month-old infants, in response to social and non-social stimuli. We demonstrated task- and frequency-dependent coupling between neural oscillatory activity, haemodynamics and metabolism. Development of simultaneous multi-modal neuroimaging methods opens new vistas in understanding brain functional specialisation. Continue reading
Sa-003-Visual cognition and dyadic interactions in caregivers and infants.
This study investigated whether there was an association between caregiver and infant visual cognition, and how caregiver-infant dyadic interactions were linked to this association. Visual cognition was measured using the preferential looking task. Caregivers and infants also engaged in unstructured play with toys. fNIRS was used to record brain activation. We found that there was an association between caregiver and infant visual cognition during experimental paradigms, and an association between caregiver and infant behaviors during dyadic interactions. Lastly, we find robust links between visual cognition and dyadic behaviors in caregivers and infants separately. Continue reading
Fr-107-Within Subject Reproducibility of fNIRS
The reproducibility of functional Near Infrared Spectroscopy (fNIRS) acquisition over multiple sessions is not well understood. To address this, four participants completed at least ten sessions of a right-hand finger tapping task while brain activity was measured with 102 fNIRS channels. Reproducibility was quantified as the probability of significant task related activity across sessions at the channel and source levels. Individual reproducibility ranged [0.4, 1.0] across participants, spatial scale, and hemoglobin species and significantly more repeatability for oxyhemoglobin (F(1,18) = 7.81, p<0.05) and ROI based analysis (F(2,18) = 4.48, p<0.05). Increasing reproducibility can further improve fNIRS utility in clinical settings. Continue reading