Transcranial focused ultrasound neuromodulation (tFUS)

The use of low-intensity, focused, typically sub-thermal ultrasound to reversibly excite or suppress neural activity in a targeted volume, non-invasively and without genetic modification. Its distinctive advantage over transcranial magnetic or electrical stimulation is millimetre-scale focal spots that can be steered to deep structures such as the thalamus, at depths those methods cannot reach selectively.

Human studies have reported modulation of motor, somatosensory, visual, and deep targets, with both excitatory and suppressive outcomes depending on parameters such as pulse duration, duty cycle, and intensity. The effects reported to date are generally modest, variable across subjects and labs, and their mechanism and even their directness remain contested — making rigorous sham control and full dose reporting essential.