Research Paper Volume 13, Issue 16 pp 19996—20015

Figure 2. Oscillatory response to electrical stimulation. (Left): Time-frequency spectrogram over the sensorimotor cortices (M0443) revealed robust broadband gamma responses (i.e., 30-75 Hz) following the first and second stimulation of the right median nerve. Time is denoted on the x-axis (in ms) and frequency is denoted on the y-axis (in Hz), with units being the percent power change from baseline (-700 to -300 ms). A color scale bar denoting the directionality of this change is shown to the right of the graphic. Grand-averaged beamformer images (i.e., across all participants and both stimulations) revealed strong increases in gamma activity in the contralateral hand region of the primary somatosensory cortex (inset in top right). (Right): The neural time course of the relative power envelope (30-75 Hz band) was extracted from the peak voxel in the contralateral somatosensory cortex and is shown averaged across all participants. Oscillatory responses to the second stimulation in the pair were strongly attenuated compared to the first (box plot inset in top right), indicative of significant gating of gamma activity across all participants. ***p < .001.