Focused ultrasound provides a more optimised solution than other traditional non-invasive neuromodulation techniques given its superior spatial specificity and penetration depth. However, due to attenuation and dispersion effects, it has not been widely used for human neuromodulation. This study presents a pioneering attempt to activate language-associated brain circuits through the use of focused ultrasound stimulation (FUS) on acupoints in human limbs, thus bypassing the distorting effects. When FUS was delivered to Tongli in the arm and Xuanzhong in the leg, significant increase in fMRI BOLD signal was recorded in language regions including the bilateral insulae and the left inferior parietal lobule. However, when FUS was delivered to the sham acupoint, Waiguan, no significant activation in cortical language regions was evident. We conclude that FUS delivered upon language-related acupoints can be used to modulate human cortical language function, which sheds light on the neurophysiological mechanisms of human language and treatment options for language disorders.
J. Liu, S. Qiu, X. Chen, Y. Zhou, J. Wu, T. Sun, D. Yuan, H. Tian, V. P. Y. Kwok, J. Tang, L. H. Tan, Focused ultrasound stimulation on human language-related acupoints modulates brain activity in cortical language processing regions, Human Behaviour and Brain1(1), 22-27 (2020).