Article Figures & Data
Figures
- Figure 1.
Experimental paradigm. ITI, Intertrial interval; ISI, interstimulus interval.
- Figure 2.
Location of recording sites in the MNI-defined space. A, Example trajectory of the DBS lead through the left STN shown on the DISTAL atlas by Ewert et al. (2018). B, MNI-defined coordinates (in millimeters) of recording sites in the STN plotted for all subjects in 3D space. C, Reconstructed locations of all ECoG electrodes in the sensorimotor cortex that were included in the study (n = 125), coregistered, and plotted on the cortical surface of the MNI brain space. D, MNI-defined coordinates (in millimeters) of the ECoG contacts on the sensorimotor cortex plotted for all subjects in 3D space. In B and D, each subject's electrodes are mapped with a different color.
- Figure 3.
STN and sensorimotor cortex (SMC) show speech-production-related time–frequency modulations. A, B, Grand average of STN (A) and SMC (B) oscillatory activity (average z-scored spectral power) across all recording sites and all trials aligned to vowel onset (time = 0 s, gray dashed vertical line). Significant modulations compared with baseline are marked in red contour (Wilcoxon's signed-rank test, p < 0.05, FDR corrected). Average speech production onsets and offsets are marked with gray dotted vertical lines. Rectangles with gray solid lines mark the time window (±500 ms from vowel onset) for the analysis of speech production-related high-gamma (60–150 Hz) activity. C, D, z-scored high-gamma (60–150 Hz) power averaged for the 1 s time window (±500 ms from vowel onset) plotted in 3D space for each subject's STN (C) and SMC (D) recording site. The location of recoding sites is provided in MNI coordinates.
- Figure 4.
Spatial distribution of tongue- and lip-preferred articulatory activity in the MNI-defined STN space and sensorimotor cortex (SMC). A, C, Outcome of a series of t tests comparing z-scored high-gamma power (averaged for a 500-ms-long time window before vowel onset) during articulation of tongue consonants versus lip consonants for each STN (A) and SMC (C) recording site. Opacity of the circles varies with the magnitude of the t-value: negative t-values (in blue shades) suggest a greater response to tongue; positive t-values (in red shades) suggest a greater response to lips (Welch's two-sample t test, p < 0.05). Note that the obtained t-values for the SMC sites differed significantly along the ventral–dorsal and lateral–medial axes (Spearman's rank-order correlation test, p < 0.01), suggesting articulator-discriminative somatotopy. Circles with black outline mark representative sites for tongue and lips, the articulatory activity of which is plotted on the right. B, D, Examples of representative tongue-preferred and lips-preferred sites for STN (B) and SMC (D). A subtraction time–frequency representation is shown for the tongue-preferred site after time–frequency representation for all trials with lip consonants is subtracted from time–frequency representation for all trials with tongue consonants (i) and for the lip-preferred site after time–frequency representation for all trials with tongue consonants is subtracted from time–frequency representation for all trials with lip consonants (iii). Gray-filled contours mark significant time–frequency differences between the two conditions (Wilcoxon's rank-sum test, p < 0.05, FDR corrected). Rectangles with gray solid lines mark the time window (from 500 ms before vowel onset until vowel onset) for the analysis of articulator-specific high-gamma (60–150 Hz) activity. Differences in averaged z-scored high-gamma power elicited by trials with the tongue articulation versus the lip articulation are shown for tongue-specific (ii) and lip-specific (iv) sites (significant differences are marked with asterisks, Welch's two-sample t test, p < 0.05). Gray bands mark the time window (from 500 ms before vowel onset until vowel onset) across which high-gamma power was averaged for the analysis of articulator-specific activity. Throughout i–iv, gray dashed vertical line represents vowel onset (time = 0 s). Dotted vertical lines represent spoken response onsets and offsets for trials with tongue consonants (blue) and trials with lip consonants (red).
- Figure 5.
Time course of the articulatory encoding at articulator-discriminative recording sites in the STN and sensorimotor cortex (SMC). A, B, Average high-gamma activity at the STN (A) and SMC (B) articulator-responsive recording sites for trials with word-initial tongue (coronal) and word-initial lip (labial) consonants. C, Number of articulator-responsive electrodes in the STN (a total of 23%) and SMC (a total of 30%) broken down by articulator type. D, Distribution of the effect sizes (Hedges' g) quantifying the difference in average z-scored high-gamma power between trials with word-initial coronal and word-initial labial consonants at each time point of the STN and SMC recordings. Throughout A, B, and D, gray dashed vertical lines represent vowel onset (time = 0 s) and dotted vertical lines represent consonant onset.
Tables
Subject Gender Age Handedness Education, y Duration of disease, y Hoehn and Yahr stage UPDRS score (off medication) 1 Male 71 Not recorded Not recorded 6 2 35 2 Male 60 Right 12 14 2 53 3 Male 69 Right 14 9 2 46 4 Male 61 Right 16 5 2 31 5 Male 68 Left 16 8 2 50 6 Male 57 Not recorded Not recorded 7 2 44 7 Male 82 Right 16 8 2 36 8 Male 66 Right 19 7 2 45 9 Female 71 Right 16 8 2 24 10 Male 77 Right 18 10 2 27 11 Male 60 Right 13 6 2 39 Subject Cortical recording No. of cortical electrode contacts STN recording No. of STN electrode contacts Rejected trials, % Mean no. of included trials per session Spoken response latency (SD), s Spoken response duration (SD), s 1 Yes 6 Yes 6 34.2 66 1.60 (0.40) 0.59 (0.13) 2 Yes 28 Not used Not used 20.8 92.5 1.70 (0.60) 0.77 (0.20) 3 Yes 6 Yes 12 4.5 110 1.18 (0.50) 0.52 (0.09) 4 Yes 54 Yes 6 4.2 110.5 1.12 (0.38) 0.65 (0.14) 5 Yes 28 Yes 6 4.6 103.5 0.70 (0.12) 0.62 (0.17) 6 Yes 6 Yes 6 5 110.5 1.27 (0.43) 0.46 (0.11) 7 Not used Not used Yes 9 22.3 59.3 2.62 (1.83) 0.43 (0.08) 8 Yes 28 Yes 12 2.1 114 0.85 (0.33) 0.63 (0.13) 9 Yes 6 Yes 6 8.6 91.67 1.12 (0.49) 0.97 (0.36) 10 Not used Not used Yes 4 12.7 75.5 1.21 (0.43) 0.54 (0.10) 11 Yes 36 Yes 12 7.1 105.3 0.99 (0.65) 0.43 (0.11)
