Current Projects

Adults with Cerebral Palsy

The goal of this study is to explore the role of visual dependence on balance instability in adults with CP. We hypothesize that adults with CP will exhibit more sensitivity to visual field motion than do healthy young adults while maintaining an upright posture in an active environment. With this established, we can develop techniques to employ this visual dependence to induce compensation for balance instability and reduce the risk of falls. The specific aims of this study are: 1) to determine the degree of visual dependence/independence in the adult with CP using the Rod and Frame test, and 2) to determine the relationship between visual dependence and postural responses when immersed in a moving visual environment in adults with CP.

Three Modality Sensory ReWighting During Standing

The primary trio of modalities that are crucial for flexible postural control are the visual, vestibular and proprioceptive systems. A primary goal of our research group has been to investigate the processes underlying the fusion of these modalities. 

Conceptually, one can decompose sensory feedback into individual feedback components from each sensory modality. These modalities are not processed independently; when sensory conditions change an adaptive process known as sensory re-weighting changes the relative importance of each modality in a coordinated fashion.

We now propose for the first time, to simultaneously perturb upright stance with all three modalities. To our knowledge, this has never been achieved experimentally. Our goal is to understand how visual, vestibular, and proprioceptive feedback are re-weighted so that overall feedback remains suited to stabilizing upright stance.

Promoting Functional Communication Abilities in Aphasia with Virtual Reality Environments

This project serves as an innovative form of therapy. The virtual reality environment will be useful in diagnosing as well as treating clients with cognitive neuropsychological disorders and speech and language disorders, such as aphasia. Aphasia is a disorder that results from brain damage in areas responsible for language. Aphasia impairs the ability to speak and understand others, and many people with aphasia experience difficulty reading and writing. The creation of the virtual reality environment consists of software development, designing and modeling an environment in 3D. The model is created in a way to give users a feeling that the environment really exists and that the users are actually part of it. The program is very interactive, with communication between the users and the avatars. The virtual reality environment therapy sessions will emulate real life and every day situations, making it very useful for realistic skill building and training. Through the use of avatars, users will inhabit and interact within their virtual reality environment. The avatars help to create personal relationships and make the application more productive. The avatars, which are modeled after humans, have emotional, and perceptive abilities. The training sessions and programs will be modified by the therapist working with individual clients, according to the needs of each client. The computer created and supported cognitive and language therapy, supports learning by making it possible for repetitive administration of therapy in the home or in a clinical setting.

Tonic neuromuscular processes in the healthy, aging,
and Parkinson’s disease

The long-term goals of this research are to understand the tonic processes underlying postural and motor control and determine how these are affected by aging and neurologic disease (primarily Parkinson’s Disease). We are investigating muscle activation patterns and after-effects in young adults and healthy, older adults. We want to determine if the central neuronal degeneration seen in Parkinson’s disease alters these activation patterns.

Effects of Vibratory Noise on Responses to Visual Input and Postural Stability

The peripheral tactile afferents provide information to the central nervous system (CNS) which contributes to human balance control. In a tactile system, the foot plantar surface receptors (mechanoreceptors) contribute its role in standing balance and movement control. Tactile stimuli, detected by the cutaneous mechanoreceptors (Meissner’s corpuscles, Pacinian corpuscles, Merkel’s disks and Ruffini endings) provide the CNS with information about spatial distribution of stimulation that is translated into a body position indicating the direction and amplitude of the body inclination. Studies have shown that the application of noise lowers vibrotactile threshold thus increasing vibrotactile sensitivity. The addition of noise in a system can enhance the detection and transmission of weak somatosensory signals through a mechanism called stochastic resonance. Subjects will be immersed in a three-dimensional complex textured scene stereoscopic visual scene generated by the virtual environment and vibratory noise is applied to the foot plantar surface. The effect of the vibratory noise in response to visual input will be analyzed across multiple populations.