Hypophonia in Parkinson’s disease: Neural correlates of voice treatment revealed by PET
Liotti, M., Ramig, L. O., Vogel, D., New, P., Cook, C. I., Ingham, R. J., Ingham, J. C., & Fox, P. T. (2003) Hypophonia in Parkinson’s disease: Neural correlates of voice treatment revealed by PET , Vol 60(3), 432-440
This study examined brain activation changes using positron emission tomography (PET; a procedure that allows a physician to examine the brain) in five individuals with idiopathic Parkinson’s disease after treatment with the Lee Silverman Voice Treatment method. This voice treatment method involves intensive voice and loudness training, including 16 sessions, four times a week, over a 1-month period. The results found that successful voice treatment is accompanied by increases in activity in certain parts of the brain during the production of sound, and decreases in other parts of the brain during the production of sound and reading. These findings, though preliminary, provide the first evidence linking voice treatment of hypophonia (decrease in volume of speech) in PD to specific neural correlates (specific parts of the brain) during speech tasks.