Dear Brian, To answer your questions would take up a lot of pd listserver space and I feel that is unfair to the majority of readers who may not be interested in this topic. So instead I'll direct you to a web site which has published a somewhat older version of my paper. It will also be published in the current issue of Cyber Psychology and Behavior. go to the HIT lab site at: http://www.hitl.washington.edu/ Next select publications Next type "Riess" in the simple search section Then you will be able to download my paper in MS Word = Riess, Thomas (1999). Visual Cues and Parkinson's Disease (Technical Report R-99-10). Seattle, Washington USA: University of Washington