Research Projects

Summary The human brain is a large, well-connected, and dynamic network. Using functional MRI data, modeling how this network processes the stimulus information has yielded insight on some of the mechanisms of the brain. However, the past efforts, including ours, on using small-scale models yielded limited understanding of how the complete and dynamic neural system functions in task-related experiments. Such understanding cannot be recovered from the data without substantial and collaborative efforts on model development.

A central goal of neuroscience is to understand how learning is implemented by the nervous system. However, despite years of studies in animals and humans, our understanding of both the computational basis of learning and its implementation by the brain is still rudimentary. A critical gap therefore exists between the large amount of behavioral and neural data that has been collected during learning and a mathematical and biological understanding of the rules governing motor plasticity.

Project Summary Calcium imaging methods allow us to record the simultaneous activity of many neurons with single-cell resolution; these methods are therefore a critical enabling tool for the BRAIN initiative and in neuroscience more broadly.

Project Summary Autism spectrum disorder (ASD) is a heterogeneous disorder characterized by repetitive and stereotyped be- havior and difficulties in communication and social interaction. It is now one of the most prevalent psychiatric disorders in childhood, but it is also a lifelong condition, adversely affecting an individual's social relationships, independence and employment well into adult.

Abstract The overarching goal of this proposal is to learn how large groups of neurons interact in a network to perform computations that go beyond the individual ability of each cell. Our working hypothesis is that emergent behavior in neural networks results from their organization into a hierarchy of modular sub-networks or motifs, each performing simpler computations than the network as a whole.

Project Summary/Abstract According to the BRAIN 2025 working group report, there is a need to drastically improve the spatiotemporal resolution of positron emission tomography (PET), in order to facilitate the translation of new tracers that target neuroreceptor function and dynamic PET imaging on the mi

Project Summary A complete understanding of both normal brain function and neurological disorders / mental illness will require the deciphering of the complex brain networks that underlie behavior and cognition, at both whole-brain and microscopic scales. The difficulty of structurally and functionally mapping these brain networks in living human subjects with sufficient sensitivity and resolution to understand normal function and detect pathological change represents a fundamental challenge.

Abstract: Our brain is a complex network with multiple levels of organization in white matter (WM) and gray matter (GM). The axonal and dendritic organizations of local GM tissue form one of the structural bases of normal brain functions. In addition, recent histopathology evidence has consistently demonstrated alterations in GM architectures in several neurological diseases, e.g., the Alzheimer's disease, multiple sclerosis, autism and epilepsy. Capturing these microstructural changes using non-invasive imaging techniques is extremely important but has not been achieved.

Project Summary/Abstract With this grant application we aim to dramatically improve over the capabilities of functional near-infrared spectroscopy (fNIRS) by developing a completely novel approach to measure human brain function.

Abstract Very recently, the revolutionary technology of contrast enhanced super-resolution ultrasound imaging has been developed. This novel technique images microvessels at resolutions as small as ten micrometers, over an order of magnitude smaller than the ultrasound diffraction limit, and at depths much greater than traditional limits imposed by the frequency.