Noninvasive neurostimulation offers an exciting method to modulate brain activity to explore function and mechanism, with translational implications. However, the methodology has a few limitations. First, targets are restricted to the surface of the cortex, unless using invasive techniques such as deep brain stimulation. Second, stimulation is non-focal, making it difficult to target specific regions of the brain.

Transcranial ultrasound solves many of these issues. Energy is focused through the skull at millimeter resolution to reach deep brain structures, with a proven safety record.  I conducted some of the first experiments on humans using focused ultrasound, showing that very brief sonication