[P‐055]: Computer mouse motion analysis in computerized screening tests for dementia: Interaction design and analysis
Amos D. Korczyn, Vered Aharonson · Alzheimer s & Dementia · 2005
In many neuropsychological tests the examinee has to point or draw on a paper template. When adapting such tests to the computer, the mouse, the cursor movements on the screen are use instead. Computer mouse usage, however, poses problems which are even more severe than keyboard usage, particularly on elderly, computer naive people. On the other hand, a wealth of data can be derived from analysis of the mousemovement. We studied methods for interaction design and analysis to enhance both usability and interpretation of computerized tests using mouse. We have adapted to computer a cognitive screening test (“strike out a symbol”) with the mouse as a user's input device. The computer adaptation was designed in a usability lab scenario, with subjects’ comments and performance evaluation as guidelines for the design. The test consisted of 3 successive segments in which the interaction gradually become more complex. The test was administered to 76 subjects, over 50 years old (53 were computer naı̈ve). 35 of the subjects were referred to a memory clinic with complaints on memory impairment while the remainder 41 were age matched controls. Prior to the test, all subjects performed at least 4 computerized cognitive tests that involved keyboard presses, which lasted not more than 30 minutes. The complete session took 40 minutes or less for all subjects. The subjects’ performance was primarily analyzed by response correctness (striking out the correct symbols). Spatial motion analysis determined features related to the quality of cursor movement. Metrics were developed to evaluate speed, variance from expected trajectories and jerkiness. In addition mouse clicking patterns where quantified. Only 22 out of 35 memory clinic subjects (compared to 39 out of the 41 controls) were able to complete the test. Different patterns were observed in the cursor movement metrics between skilled and computer naı̈ve subjects, and between the control and memory impaired group, in either computer skilled or computer naive groups. The results imply that computer mouse interaction may be valuable in screening subjects with memory impairment, but that the interface should be carefully designed to overcome usability problems.