Facilitating Mindfulness Training with Ultrasonic Neuromodulation

This randomized trial tested whether suppressive transcranial focused ultrasound (tFUS) targeting the posterior cingulate cortex during mindfulness training altered equanimity and resting-state default mode-central executive network (DMN-CEN) connectivity in novice meditators. Thirty meditation-naive adults were randomized to active or sham tFUS; 24 completed a 2-week Body Focus program (active n = 16; sham n = 8), including 14 daily lessons and four tFUS-meditation sessions. Resting-state fMRI scans were acquired and the Equanimity Scale-16 (ES-16) was administered before and after the meditation training intervention. Voluntary meditation practice time was measured during four tFUS-meditation sessions during training. DMN-CEN connectivity showed an interaction (β = −0.118, 95% CI [−0.186, −0.050], p = 0.002), reflecting decreased connectivity in Active and a nonsignificant increase in Sham. Greater DMN-CEN decreases were associated with greater ES-16 Acceptance increases across participants (β = −22.93, p = 0.031). The estimated relation between connectivity change and voluntary practice duration differed in direction by condition, but the interaction was not significant (β = −51.69, p = 0.061). PCC-targeted tFUS combined with mindfulness-based training was associated with resting-state connectivity differences but not differential change in the ES-16 total score. Replication in a larger, fully blinded trial is needed. The preregistration specified a target of 80 participants with 1:1 allocation ( https://osf.io/pe6d4/ ). Resource-related changes made before outcome examination resulted in 30 randomized participants, of whom 24 completed. Because the connectivity hypothesis was underspecified, the connectivity analyses and non-preregistered ES-16 subscale analyses were treated as exploratory.