Novel Dynamic Methods of TACS
Transcranial alternating current stimulation (TACS) is an emergent method of non-invasive neuromodulation that can engage frequency-specific brain oscillations. We propose a new application of multi-channel TACS to hyper- or de-synchronize distant brain regions by driving them with the same frequency but at different phases.
Multi-Scale Modeling from Whole Brain to Single Neuron Level
TES applies an electric current at the scalp in order to modulate ongoing brain activity. Simulations play an important role in exploring TES mechanisms. Here, we are developing a multi-scale approach: first, we simulate TES in a realistic head model to find the electric field at each location. Then, we use the NEURON framework to simulate the behavior of individual realistic neurons. This method gives an in-depth insight into the mechanism of action and target engagement during TES.
Closed-Loop Real-Time TMS-EEG in Humans
TMS enables non-invasive perturbation of brain activity in humans. Its repeated application over the left prefrontal cortex is effective for the treatment of depression. However, there is significant variability in treatment outcomes across patients. We hypothesize that aligning TMS pulses to the "context" of the ongoing brain activity (EEG) using a closed-loop real-time approach will improve the effectiveness of the stimulation.
Brain Stimulation for Stroke Recovery in Children
Ischemic perinatal stroke affects as many as 1 in 2,300 live births. Transcranial magnetic stimulation (TMS) and transcranial electric stimulation (TES) have shown promise as noninvasive cortical assessment and neuromodulation techniques for stroke rehabilitation. We are integrating individual realistic head models into the therapy to optimize neuromodulation targets for rehabilitation in perinatal stroke. Using our novel computational method, we are able to develop more precise and effective personalized treatments for stroke rehabilitation.
(Left) Individual head models from patients' MRI are made using the finite element method (FEM). Anatomically accurate representation of a lesion is a crucial step for patient-specific modeling. (Right) Simulation of the electric field during TMS over the lesioned (left) and non-lesioned (right) hemispheres. A) TMS coil over the motor cortex. B) TMS coil over the temporal lobe. We conduct FEM simulations to understand how electric fields change for different brain anatomy and in the presence of a lesion.
Cross-Species Modeling for Translational Research