Is Ultrasonic Brain Stimulation The Future?

A paper just out in Nature Neuroscience proposes a new tool for neuroscientists who want to stimulate the brain - ultrasound. There are already a number of established ways of modulating human brain activity. As neuronal firing is essentially electrical, most of these methods rely on electricity - such as TDCS - or on magnetic fields, which induce electrical currents - as in TMS. Now Virginia Tech researchers Wynn Legon and colleagues say that a very different approach, ultrasound, could be the next big thing: Transcranial focused ultrasound modulates the activity of primary somatosensory cortex in humans Ultrasound for neurostimulation is not an entirely new idea. It's been shown to work in cell cultures and in animals, but this is the first attempt in humans. The idea is simple: focus a beam of sound waves at a very high frequency (500 kHz, about 25 times too high for humans to hear) through the skull and into the brain. This, we are told, modulates neuronal firing - although it's not clear quite how. Legon et al write: