Life Sciences Commons^™

Investigating Task-Free Functional Connectivity Patterns In Newborns Using Functional Near-Infrared Spectroscopy, Homa Vahidi

Electronic Thesis and Dissertation Repository

Robust functional connectivity in sensorimotor resting-state network (RSN) has been linked to positive neurodevelopmental outcomes in neonates. In the current study, we aimed to map the developmental trajectory of sensorimotor RSN in awake neonates using functional near-infrared spectroscopy (fNIRS). We acquired fNIRS resting-state data from 41 healthy newborns (17 females, gestational age range=36+0 to 42+1 weeks) within the first 48 hours after birth. At the group level, we observed robust positive connectivity in numerous channel-pairs across the sensorimotor network, especially in the left hemisphere. Next, we examined the relationship between functional connectivity, gestational age and postnatal age, while controlling for …

Towards Clinical Microscopic Fractional Anisotropy Imaging, Nico Jj Arezza

Electronic Thesis and Dissertation Repository

Microscopic fractional anisotropy (µFA) is a diffusion-weighted magnetic resonance imaging (dMRI) metric that is sensitive to neuron microstructural features without being confounded by the orientation dispersion of axons and dendrites. µFA may potentially act as a surrogate biomarker for neurodegeneration, demyelination, and other pathological changes to neuron microstructure with greater specificity than other dMRI techniques that are sensitive to orientation dispersion, such as diffusion tensor imaging. As with many advanced imaging techniques, µFA is primarily used in research studies and has not seen use in clinical settings.

The primary goal of this Thesis was to assess the clinical viability of …

Category Learning Dlpfc Single-Dissociation By Fnirs, Tim Qiu

Electronic Thesis and Dissertation Repository

It remains an open question whether modern neuroimaging clearly dissociates the Explicit system that learns by encoding rules, and the Implicit system that learns by encoding information-integration boundaries. Further, there are nearly no applications of fNIRS as a modality in studying category learning. We conduct two behavioural experiments to validate a carefully controlled categorization task intended to dissociate Explicit and Implicit systems. Then we apply fNIRS neuroimaging within-subjects to localize a neuroanatomical dissociation. We localized two effects to R DLPFC (1) a simple single-dissociation of higher activity in RB categorization, and (2) a negative relationship between overall task performance and …