Figure 5. SEEG responses to speech mental imagery.
(a) Subject one with contacts in the left operIFG, middle STG, posterior INS and anterior SMG. Significant spectral responses at 0.8 Hz were detected in the operIFG, and the remaining contacts were responsive to the 4 Hz frequency. (b) The cluster including the operIFG from MEG sources is presented in the upper panel. The electrode with contact in the operIFG in Subject one was projected in the MNI space and is shown in the lower panel. SEEG localization supports the MEG source estimation results. (c) Averaged time course of high gamma activity in the operIFG in Subject 1. Periodical changes presented every 1.25 s (0.8 Hz) with increasing amplitude near the onset of the last number (black arrow) in each mentally constructed group under the mental imagery condition (red line) but not the baseline condition (blue line). (d) Subject two with contacts in the left HG. Significant spectral peaks were observed at 4 Hz in the HG. (e) Subject three with contacts in the right middle STG. Significant spectral peaks were observed at 4 Hz in the middle STG. (f) Contact locations in the MNI space. Different colored marks represent each subject’s responsive contacts with significant spectral peaks at 0.8 Hz and/or 4 Hz. Gray marks represent non-responsive contacts with no significant spectral peaks. (g) In each brain region with contacts responsive at 4 Hz, the normalized peaks were significantly larger than zero under the baseline condition (blue stars). Among these peaks, the normalized peaks were significant in the left posterior INS, left anterior SMG, left HG and right middle STG (red stars). The peaks in the bilateral middle STG were smaller under the mental imagery condition than the baseline condition (gray stars). ***p<0.001, **p<0.01, *p<0.05.
Figure 5—figure supplement 1. SEEG results of subjects 4–5.
