Implication of auditory confounding in interpreting somatosensory and motor responses in low-intensity focused transcranial ultrasound stimulation

Low-intensity transcranial focused ultrasound (LI-tFUS) stimulation is a noninvasive neuromodulation tool that demonstrates high target localization accuracy and depth penetration. It has been shown to modulate activities in the primary motor and somatosensory cortex. Previous studies in animals as well as in humans, illustrated in the recently published paper in Brain Stimulation by Braun et al. [Braun V, Blackmore J, Cleveland RO, Butler CR. Brain Stimul 13: 1527–1534, 2020], acknowledged the possibility of indirect stimulation of the peripheral auditory pathway that could confound the somatosensory and motor responses observed with LI-tFUS stimulation. Here, we discuss the implications and interpretations of auditory confounding in the context of neuromodulation.