To further understanding of brain function in health and disease, our lab is focused on basic science and clinical applications including development of high density diffuse optical tomography (HD-DOT) methods, applying HD-DOT to studies in childhood development, and expanding analytical methods for relating brain function based connectomes to behavior, exposure and outcome. See below for some additional information on these primary aims of the lab.
HD-DOT Methods Development
The loud and constraining nature of MRI-based neuroimaging severely limits studies on direct within-room social communication, on auditory processing and language generation, and presents an excessively challenging setting for sensitive participants, such as school-aged children and in particular young infants, toddlers, and those severely affected with autism spectrum disorder. Near-infrared spectroscopy (NIRS) based methods measure variations in the time course of a signal between a source of safe near infrared light and a detector. When placed on the head, NIRS recovers underlying cerebral hemodynamic variations. High-density diffuse optical tomography (HD-DOT) employs a high-density grid of sources and detectors to provide the overlapping measurements necessary to obtain image quality comparable to fMRI. We have developed HD-DOT systems that can accurately map distributed brain activity within the outer ~1.5 cm of cortex in response to tasks, cortical resting state networks (RSN) during quiet rest and sleep, and distributed brain activity during movie watching. HD-DOT has greater comfort than fMRI (participants sit upright in a comfortable chair), and has comparable temporal and spatial resolution to fMRI. Dynamic measures of brain function are thus accessible without requiring super-cooled magnets and the constraints of the MRI bore and head coils. HD-DOT is inherently portable and deployable in natural settings more amenable to assessing brain function in young children than other common functional brain imaging technologies.
In addition to further advancing the Continuous Wave HD-DOT systems within the lab, we are also developing Frequency Domain HD-DOT systems that incorporate additional phase information capable of further improving image quality obtainable with optical systems. Please see here for a recent news article (https://www.sciencedaily.com/releases/2019/08/190821135246.htm).
An ongoing and long-term focus of our lab is to advance HD-DOT methods for evaluating brain-behavior relationships in infants, toddlers, and school-aged children who are typically developing, have a diagnosis of autism spectrum disorder (ASD), or who are at risk for developing ASD. HD-DOT supports imaging brain function while children are awake and engaged within a naturalistic setting. A neurodevelopmental disorder affecting 1/59 children in the general population, ASD is defined by social communication deficits plus repetitive behaviors and restricted interests. Neuroimaging methods, including both task-based functional magnetic resonance imaging (fMRI) and task-free functional connectivity MRI, have demonstrated sensitivity to neural signatures of ASD that may inform diagnosis and track responses to interventions. However, the MRI environment can prove intolerable for many children due to noise, claustrophobia, and the need to lie supine and still. HD-DOT provides a compelling alternative that overcomes the significant ergonomic limitations of fMRI and silently images brain function with a wearable cap in a naturalistic setting ideal for studies on awake and engaged infants and toddlers. If you have a child under the age of 18 and are interested in participating in our research, please see the For Parents and Participants tab.