This phase I project will develop a computer-based tool for the functional assessment of higher level instrumental activities of daily living (IADLs) using simulated activities in a virtual environment (VE). IADLs are the high level activities such as managing finances and complex medication regimens and successfully negotiating novel or new situations that are necessary for fully independent living and which can be compromised by cognitive impairment in older individuals. Indeed, ability to conduct one's usual and typical ADLs is the sine qua non of successful aging. It is frequently the basis for determining whether an older individual is able to live independently and is a core criterion for the diagnosis of dementi. However, valid and reliable measurement of IADLs is difficult. Many existing scales were designed for use with patients with known cognitive impairment and focus on basic activities that are not sensitive to the decline in higher level behaviors that begins well before a dementia diagnosis is made. Most are based on an informant's or the individual's own rating of their abilities. Such an approach has the problem that, for a variety of reasons, individuals and informants may over- or under-rate the person's skills. The range of possible scores is also often limited. Virtual reality using computer simulated environments is an obvious vehicle for the reliable assessment of a range of functional activities. The ultimate goal is to use virtual environment technology to develop a tool that will accurately measure performance across a range of high level functional tasks in older individuals with very mild dysfunction. The proposed tool, Functional Assessment using a Virtual Environment (FAVE), will offer five environments across a range of difficulty. The FAVE tasks (telephone use, medication management, managing finance, household activities and travel using public transportation) have been identified in the literature as activities that are both crucial for independent living and susceptble to subtle impairment. In Phase I, we will use a task analysis approach to prepare scripts and story boards for each scenario, submitting them to a focus group of experts for comments and, if necessary, modification. Two virtual environment scenarios will be implemented using the Unity 3D cross platform game engine. Tasks will be executed on tablet based mobile devices (iPad, Galaxy Tab). The participant will interact with the tablet via a stylus or finger touch with responses accurately time stamped (milliseconds). Eye-tracking and facial expression data will be collected and analyzed during the entire test session. The completed scenarios will be reviewed by expert focus groups and piloted on 10 normal older individuals and 10 persons with mild cognitive impairment to determine the ability of FAVE to detect subtle difficulties in IADLs and identify any necessary changes. In Phase II any final changes would be made before implementation in final product which will be validate in an extensive study comparing FAVE results against actual performance in a large number of subjects.
Evaluation of performance in activities of daily living (ADLs) is essential in determining whether an older individual is able to live independently, ADL impairment is associated with many cognitive disorders of aging, and is a core criterion for the diagnosis of dementia, and specifically for Alzheimer's disease (AD). Therapeutic intervention that could delay the placement of older individuals into long term care settings by a few years could significantly reduce Medicare costs by hundreds of billions of dollars; however, existing tools for functional assessment are not sensitive enough to the very earliest signs of decline. We will provide an innovative performance-based measure of functional ability using a virtual environment that targets mild dysfunction across a range of high level functional tasks to address this unmet need.
