Fig. 4: Changes in GABA+/water after transcranial ultrasound stimulation (TUS).

Concentrations of GABA+/water in n = 24 individuals are shown in the a dorsal anterior cingulate cortex (dACC) voxel and b posterior cingulate cortex (PCC) voxel after each TUS session and sham. The active TUS session (i.e., when TUS was applied to and measured in the same region) is shown in the middle of both plots, to aid in the visual comparison against the sham and the control TUS sessions. The grey lines link measurements from the same individual across TUS sessions. The bold pink line represents the mean and standard error of the mean for each session. An ANCOVA and post hoc two-sided t tests with Holm adjustment for multiple comparisons were performed for each MRS voxel location (*p < 0.05, n.s.: not significant). ANCOVA in the dACC voxel did not show a significant main effect of session. ANCOVA in the PCC voxel showed a significant main effect of session, F(2,55) = 4.66, p = 0.013, η² = 0.141. Post-hoc comparisons were statistically significant for PCC TUS vs sham, t(55) = −2.88, p = 0.017, Cohen’s d = −0.92, 95% Confidence Interval (CI) = [−1.578, −0.254], and PCC TUS vs dACC TUS, t(55) = −2.32, p = 0.048, Cohen’s d = −0.73, 95% CI = [−1.383, −0.084], with no significant difference between dACC TUS and sham, t(55) = −0.57, p = 0.570, Cohen’s d = −0.18, 95% CI = [−0.823, −0.458]. Source data are provided as a Source Data file.