In 2009, researchers led by Lauren K. King of the Sun Life Financial Movement Disorders Research and Rehabilitation Centre at Wilfrid Laurier University, in Waterloo, Ontario, found that short-term use of vibroacoustic therapy with Parkinson's disease patients led to improvements in symptoms, including less rigidity and better walking speed with bigger steps and reduced tremors ( NeuroRehabilitation , December, 2009). In that study, the scientists exposed 40 Parkinson's disease patients to low-frequency 30-hertz vibration for one minute, followed by a one-minute break. They then alternated the two for a total of 10 minutes. The researchers are now planning a long-term study of the use of vibroacoustic therapy with Parkinson's patients, as part of a new partnership with the University of Toronto's Music and Health Research Collaboratory, which brings together scientists from around the world who are studying music's effect on health.
There have been multiple theories regarding divided attention. One, conceived by Kahneman ,  explains that there is a single pool of attentional resources that can be freely divided among multiple tasks. This model seems to be too oversimplified, however, due to the different modalities (., visual, auditory, verbal) that are perceived.  When the two simultaneous tasks use the same modality, such as listening to a radio station and writing a paper, it is much more difficult to concentrate on both because the tasks are likely to interfere with each other. The specific modality model was theorized by Navon and Gopher in 1979. However, more recent research using well controlled dual-task paradigms points at the importance of tasks.  Specifically, in spatial visual-auditory  as well as in spatial visual-tactile tasks  interference of the two tasks is observed. In contrast, when one of the tasks involves object detection, no interference is observed.  Thus, the multi-modal advantage in attentional resources is task dependent.