Virtual Reality Assessment of Visuospatial Disorientation in Alzheimer’s
Victoria S. Pelak, M.D.
University of Colorado
2005 Investigator-Initiated Research Grant
Visual spatial dysfunction in Alzheimer’s disease (AD) results in the inability to properly navigate in the environment and to interpret three-dimensional images, objects, and visual scenes. Even when cues are present in the environment, individuals with AD still may get lost or have difficulty interpreting visual spatial relationships. Even before diagnosis, individuals may notice poor vision despite an eye exam and 20/20 vision. Numerous studies have established this as the result of visuoperceptual decline, which is independent of memory impairment and has been found to predict AD. Thus, procedures that evaluate visuoperceptual function may play a key role in recognizing manifestations of the preclinical stage of AD and provide a noninvasive marker for early and accurate detection.
Victoria S. Pelak, MD, will study three-dimensional (3D) perception in people with AD, amnestic Mild Cognitive Impairment (aMCI), and healthy older adults using virtual-reality-based tests in order to develop an early marker of AD. She believes that individuals with AD misinterpret 3D depth cues provided by objects in the environment during self-movement and that this contributes to optic flow misperception and visuospatial dysfunction.
Dr. Pelak and her team will examine this hypothesis using techniques recently developed by their research group to study recognition of 3D objects in motion. They will use a 12-foot by 12-foot by 10 foot-high, room-like, 3-dimensional, immersive, virtual-reality environment (IVE or a CAVE) to present scenes that examine the interaction between depth and motion perception of objects with a person's optic flow. They will measure each group’s ability to use visual features to perceive depth, to use depth cues to perceive visual features, and to identify 3D images of common objects. They will determine how depth cues, visual features, and 3D images of objects influence optic flow perception. This research can contribute to the development of potential markers for early and accurate detection of AD.