A5085509811- Functional Brain Connectivity Studies
- Advanced MRI Techniques and Applications
- Neural dynamics and brain function
- Visual perception and processing mechanisms
- Advanced Neuroimaging Techniques and Applications
- Face Recognition and Perception
- Atomic and Subatomic Physics Research
- Advanced Fluorescence Microscopy Techniques
- Photoreceptor and optogenetics research
- Neural and Behavioral Psychology Studies
- Ferroelectric and Negative Capacitance Devices
- EEG and Brain-Computer Interfaces
- Advanced Memory and Neural Computing
- MRI in cancer diagnosis
- Retinal and Optic Conditions
- Photoacoustic and Ultrasonic Imaging
- Optical Imaging and Spectroscopy Techniques
- stochastic dynamics and bifurcation
- Neural Networks Stability and Synchronization
- Spectroscopy and Quantum Chemical Studies
- NMR spectroscopy and applications
- Multisensory perception and integration
University of Illinois Urbana-Champaign
2024-2025
National Institute of Mental Health
2018-2022
National Institutes of Health
2018-2021
Peking University
2015-2018
Earlier research in cats has shown that both cerebral blood volume (CBV) and flow (CBF) can be used to identify layer-dependent fMRI activation with spatial specificity superior gradient-echo blood-oxygen-level-dependent (BOLD) contrast (Jin Kim, 2008a). CBF of perfusion at ultra-high field not been widely applied humans measure laminar activity due its low sensitivity, while CBV for using vascular space occupancy (VASO) successfully used. However, VASO compromised by interference in-flow...
Abstract Functional MRI (fMRI) time series are inherently susceptible to the influence of respiratory variations. While many studies treat respiration as a source noise in fMRI, this study employs natural variations during high resolution (0.8 mm) fMRI at 7T formulate effect related map and then use reduce macrovascular bias for more laminar-specific measurement. Our results indicate that respiratory-related signal changes modulated by breath phase (breathing in/out or transition between...
Abstract Cerebral blood volume (CBV) and cerebral flow (CBF) based functional magnetic resonance imaging (fMRI) have proven to be more laminar-specific than blood-oxygen-level-dependent (BOLD) contrast fMRI, but they suffer from relatively low sensitivity. In previous work, we integrated CBV CBF into one using DANTE (Delay Alternating with Nutation for Tailored Excitation) pulse trains combined 3D echo-planar (EPI) create an perfusion (VAPER) weighted (Chai et al., 2020). Building on this,...
Abstract Viewing faces that are perceived as emotionally expressive evokes enhanced neural responses in multiple brain regions, a phenomenon thought to depend critically on the amygdala. This emotion-related modulation is evident even primary visual cortex (V1), providing potential substrate by which salient stimuli can affect perception. How does emotional valence information, computed amygdala, reach V1? Here we use high-resolution functional MRI investigate layer profile and retinotopic...
Abstract Neuroscientific investigations at the cortical layer level not only enrich our knowledge of micro-circuitry in vivo, but also help bridge gap between macroscopic (e.g., conventional fMRI, behavior) and microscopic extracellular recordings) measures brain function. While laminar fMRI studies have extensively explored evoked response multiple subsystems, investigation component functional networks throughout entire has been hindered due to constraints high-resolution layer-fMRI...
The human brain continuously generates predictions of incoming sensory input and calculates corresponding prediction errors from the perceived inputs to update internal predictions. In primary somatosensory cortex (area 3b), different cortical layers are involved in receiving generation error signals. It remains unknown, however, how area 3b contribute temporal processing. To investigate representation across layers, we acquired layer-specific functional magnetic resonance imaging (fMRI)...
Transcranial alternating current stimulation (tACS) has emerged as a promising tool for modulating cortical oscillations. In previous electroencephalogram (EEG) studies, tACS been found to modulate brain oscillatory activity in frequency-specific manner. However, the spatial distribution and hemodynamic response this modulation remains poorly understood. Functional magnetic resonance imaging (fMRI) advantage of measuring neuronal regions not only below electrodes but also across whole with...
Purpose Direct mapping of neuronal currents using MRI would have fundamental impacts on brain functional imaging. Previous reports indicated that the stimulus‐induced rotary saturation (SIRS) mechanism had best potential direct detection neural oscillations; however, it lacked high‐sensitivity level needed. In this study, a novel strategy is proposed in an effort to improve sensitivity. Methods our modified SIRS sequence, external oscillatory magnetic field used as excitation pulse place...
The increased availability of ultra-high field scanners provides an opportunity to perform fMRI at sub-millimeter spatial scales and enables in vivo probing laminar function the human brain. In most previous studies, definition cortical layers, or depths, is based on anatomical reference image that collected by a different acquisition sequence exhibits geometric distortion compared functional images. Here, we propose generate with technique incorporating magnetization transfer (MT) weighted...
Abstract Purpose We investigate the influence of moving blood‐attenuation effects when using “delay alternating with nutation for tailored excitation” (DANTE) pulses in conjunction blood oxygen level dependent (BOLD) functional MRI (fMRI) at 3 T. Based on including DANTE pulses, we propose quantification cerebral volume (CBV) changes following stimulation. Methods Eighteen volunteers total underwent fMRI scans Seven were scanned to signal. CBV response visual stimulation quantified 11 a...
By using dual-echo DANTE-EPI for functional visual stimulation studies, the contrast of fractions intravascular signal to total change can be generated. We show an shifted (IVS) provide simultaneous visualization intra-extra vascular under different frequencies stimulations at 3T.
We introduced a whole-brain 3D VAPER sequence tool and analysis approach for layer-specific resting state fMRI. It allows investigation of the directional connectivity between brain areas determine whether any given connection is better described as predominantly feedforward vs. feedback driven. To exemplify this, we demonstrated that different directions same within default mode network (mPFC <-> PCC/Parietal region) lead to laminar correlation profile, suggesting projection types...
Motivation: Although fMRI has achieved sub-millimeter spatial resolution especially with ultra-high field (&ge;7T) scanners, its specificity not kept pace. Goal(s): This study aims to map and validate the influences of natural respiratory variations on signals use it improve laminar specificity. Approach: We compare patterns induced by deep breath hold tasks probe their correlation vascular density. Results: variation revealed information can be used remove macrovascular-dominated...
Emotionally expressive faces evoke enhanced neural responses in multiple brain regions, a phenomenon thought to depend critically on the amygdala. This emotion-related modulation is evident even primary visual cortex (V1), providing potential substrate by which emotionally salient stimuli can affect perception. How does emotional valence information, computed amygdala, reach V1? Here we use high-resolution functional MRI investigate layer profile and retinotopic distribution of activity...