Neuroplasticity Associated With Cortical/Cerebral Visual Impairment
In developed countries including the United States, cortical/cerebral visual impairment (CVI) is the leading cause of permanent visual impairment in children, and is characterized by visual dysfunction primarily associated with damage to central brain structures as opposed to the eyes. Despite this significant public health concern, the neurophysiology of this condition remains poorly understood, and more research is needed to fully understand how the developing brain reorganizes itself in response to early damage. The goal of this investigation is to establish a conceptual framework relating sensory function with structural and functional brain reorganization in CVI. In this effort, we use high resolution structural reconstruction and characterization of the white matter pathways of the brain using diffusion based imaging (specifically, High Angular Resolution Imaging, or HARDI). We employ behavioral assessments integrating virtual reality (VR), psychometric sequences, and eye/gesture tracking technology. These novel techniques allow us to characterize visual dysfunctions beyond what is done in the standard clinical settings using scenarios that more closely approximate real world situations.
Spatial Cognition Related to Navigation and Video Game Based Learning in the Blind
For a blind individual, learning to navigate independently and safely is a very important skill to master. Considerable interest has arisen in developing virtual reality and computer based video games as a means to motivate and improve contextual learning. In this direction, we have developed a user-centered, computer-based navigation software designed with the purpose of developing navigation skills in the blind through immersive virtual navigation. The software is called Audio-based Environmental Simulator (AbES). Using auditory spectral cues, a user navigates through a simulated virtual environment based on the spatial layout of a building for which they are previously unfamiliar. Following exploration during game play, the user is able to transfer the knowledge gained regarding the spatial layout and navigate their way in the physical building modeled in the software. Associated studies using functional MRI (fMRI) and wireless electro-encephalography (EEG) allow us to study how the brain navigates in the absence of sight.