A5065612786- Olfactory and Sensory Function Studies
- Circadian rhythm and melatonin
- Migraine and Headache Studies
- Glaucoma and retinal disorders
- Advanced MRI Techniques and Applications
- Visual perception and processing mechanisms
- Advanced Neuroimaging Techniques and Applications
- Functional Brain Connectivity Studies
- Neural Networks and Applications
- Neonatal and fetal brain pathology
- Domain Adaptation and Few-Shot Learning
- Ocular and Laser Science Research
- Vestibular and auditory disorders
- Radiomics and Machine Learning in Medical Imaging
- Neural dynamics and brain function
University of Pennsylvania
2020-2025
California University of Pennsylvania
2021-2022
From sequences of discrete events, humans build mental models their world. Referred to as graph learning, the process produces a model encoding event-to-event transition probabilities. Recent evidence suggests that some networks are easier learn than others, but neural underpinnings this effect remain unknown. Here we use fMRI show even over short timescales network structure temporal sequence stimuli determines fidelity event representations well dimensionality space in which those encoded:...
We created a set of resources to enable research based on openly-available diffusion MRI (dMRI) data from the Healthy Brain Network (HBN) study. First, we curated HBN dMRI (N = 2747) into Imaging Data Structure and preprocessed it according best-practices, including denoising correcting for motion effects, susceptibility-related distortions, eddy currents. Preprocessed, analysis-ready was made openly available. quality plays key role in analysis dMRI. To optimize QC scale this large dataset,...
Significance The melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) may contribute to photophobia in migraine. We measured visual discomfort and pupil responses cone melanopsin stimulation—the photoreceptor inputs the ipRGCs—in people with without find that migraine do not differ from those headaches how signals are weighted combined produce discomfort. Instead, is associated amplification of ipRGC for This effect upon limited photophobia, as we did an...
The primary goal of this study was to develop a parametric model that relates variation in stimulation the trigeminal nerve properties blink response. We measured responses 17 healthy, adult participants air puffs directed at lateral canthus eye five different, log-spaced intensities (3.5-60 PSI). Lid position over time decomposed into amplitude and velocity components. found systematically related log stimulus intensity, with relationship well described by sigmoidal function. parameters fit...
There is substantial variation between healthy individuals in the number of retinal ganglion cells (RGC) eye, with commensurate axons optic tracts. Fixel-based analysis diffusion MR produces estimates fiber density (FD) and cross section (FC). Using these fixel measurements along imaging, we asked if individual differences RGC tissue volume are correlated FD FC obtained from tracts, subsequent structures cortical visual pathway. We find that endowment tract FC, but not FD. had a decreasing...
Human experience is built upon sequences of discrete events. From those sequences, humans build impressively accurate models their world. This process has been referred to as graph learning, a form structure learning in which the mental model encodes event-to-event transition probabilities [1], [2], typically medial temporal cortex [3]-[6]. Recent evidence suggests that some network structures are easier learn than others [7]-[9], but neural properties this effect remain unknown. Here we use...
Abstract In addition to the rod and cone photoreceptors retina contains intrinsically photosensitive retinal ganglion cells (ipRGCs). These express photopigment melanopsin are known be involved in reflexive visual functions such as pupil response photo-entrainment of circadian rhythm. It is possible that ipRGCs contribute conscious perception, either by providing an independent signal geniculo-striate pathway, or interacting with thus modifying signals arising from “classical” combine...
To quantify interictal photophobia in migraine with and without aura using reflexive eye closure as an implicit measure of light sensitivity to assess the contribution melanopsin cone signals these responses.Participants were screened meet criteria for 1 3 groups: headache-free (HF) controls, (MO), visual (MA). MO MA participants included if they endorsed ictal photophobia. Exclusion impaired vision, inability collect usable pupillometry, history either head trauma or seizure. Participants...
Abstract There is substantial variation between healthy individuals in the number of retinal ganglion cells (RGC) eye, with commensurate axons optic tracts. Fixel-based analysis diffusion MR produces estimates fiber density (FD) and cross section (FC). Using these fixel measurements along imaging, we asked if individual differences RGC tissue volume are correlated FD FC obtained from tracts, subsequent structures cortical visual pathway. We find that endowment tract FC, but not FD. had a...
Abstract Second only to headache, photophobia is the most debilitating symptom reported by people with migraine. While melanopsin-containing, intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought play a role, how cone and melanopsin signals integrated in this pathway produce visual discomfort poorly understood. We studied 60 people: 20 without headache each interictal from migraine or aura. Participants viewed pulses of spectral change that selectively targeted melanopsin,...
Abstract Objective To assess the contribution of melanopsin-containing, intrinsically photosensitive retinal ganglion cells (ipRGCs) and cones to reflexive eye closure as an implicit measure interictal photophobia in migraine. Methods We studied twenty participants each three groups: headache-free (HAf) controls, migraine without aura (MwoA), with visual (MwA). Participants viewed spectral pulses that selectively targeted melanopsin, cones, or their combination while we recorded orbicularis...
The pupil constricts to illusory brightness, presumably mediated by a cortical mechanism. People with migraine aura (MwA) have greater discomfort and response visual stimuli. We tested if people MwA an enhanced brightness as compared migraineurs without (MwoA) headache-free controls (HaF). Our pre-registered study is of 15 subjects from each the 3 headache diagnostic categories. Pupil responses are recorded while view many, 1s presentations three different stimuli, equated in integrated...
Abstract In addition to the cone photoreceptors retina contains intrinsically photosensitive retinal ganglion cells (ipRGCs). These express photopigment melanopsin and are known be involved in reflexive visual functions such as pupil response photo-entrainment of circadian rhythm. It is possible that ipRGCs contribute conscious perception, either by providing an independent signal geniculo-striate pathway, or interacting with thus modifying signals arising from “classical” combine contrast...