Extended data figure 1. Cortical activations from intracranial recordings in right hemisphere during speech production.

a. Mean HG activations of ROIs during response onset in right hemisphere, averaged within patient. Shaded area denotes standard error. Colored horizontal bars indicate time-periods of significant activation above baseline (one-sided permutation test with cluster correction, cluster forming threshold p<0.05, 1000 permutations). b. Electrode distributions of peak HG time-points per ROI in right hemisphere. Significant differences in peak activations were observed across ROIs around the speech utterance (one-way ANOVA: F_9,781 = 6.69, p < 0.001, two-sided). Right: Electrode distributions of peak HG time-points per speech network. This temporal variation was also observed via significant differences in peak activations (one-way ANOVAs F_2,788 = 8.86, p < 0.001, two-sided). Post-hoc one-sided t-tests indicate pairwise significance between the speech networks in right hemisphere: T_Planning > T_{Articulation,} t₍₅₁₁₎ = 2.3, p = 0.021; T_Articulation < T_Monitoring, t₍₅₂₈₎ = 7.53, p < 0.001, T_Planning < T_Monitoring, t₍₃₈₅₎ = 2.36, p = 0.019).