The charity has employed marketing agency TDA to 'test' donors' preferences and help it to develop future appeals.
All supporters will receive a form asking them to become regular donors or give a one-off donation. Half will also receive a 'human touch' leaflet designed to appeal to their emotions, and the other half will instead receive a letter containing facts and figures about the charity's work and background.
The 'human touch' leaflet will contain a case study of someone living with Parkinson's disease.
The 'factual' letter will highlight the charity's Next Step Initiative, launched last autumn to help fund new research, and include details of scientific research into Parkinson's.