Figure 2.

Speech and tremor data during the counting task. Closed circles, tremor severity; open circles, speech timing measures; in the left shaded area of each panel are the clinical baseline tremor ratings (up closed triangle), the best tremor rating obtained in the study (down closed triangle). Both baseline and best performance ratings were obtained with bilateral stimulation, along with the corresponding speech scores for the same conditions (up open triangle for clinical baseline and down closed triangle for best performance). For all measures, values closer to the x-axis were considered an improvement. r values reflect correlation between speech and tremor.