TRANSCRANIAL FOCUSED ULTRASOUND ENHANCES SENSORY DISCRIMINATION CAPABILITY THROUGH SOMATOSENSORY CORTICAL EXCITATION

Low-intensity transcranial focused ultrasound (tFUS) has emerged as a non-invasive brain neuromodulation tool with high spatial specificity. Previous studies attributed tFUS-enhanced sensory performance to the ultrasound-induced inhibitory neural effects. However, to date there is no direct evidence validating the neural mechanism underlying ultrasound-mediated somatosensory enhancement. In this study, healthy human subjects (N = 9) were asked to perform tactile vibration frequency discrimination tasks while tFUS was directed onto the primary somatosensory cortex. During this task, we simultaneously recorded 64-channel electroencephalography (EEG) signals and investigated the brain responses at both EEG sensors and source domains by means of electrophysiological source imaging (ESI). The behavioral results indicated that the subjects' discrimination ability was improved by tFUS with an increased percentage of correct responses. EEG and ESI results revealed that tFUS neuromodulation was able to improve sensory discrimination capability through excitatory effects at the targeted sensory cortex. (C) 2021 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

Automated summary

This study investigated the neural mechanism underlying ultrasound-mediated somatosensory enhancement by conducting tactile vibration frequency discrimination tasks while applying tFUS onto the primary somatosensory cortex. The results showed that tFUS was able to improve sensory discrimination capability through excitatory effects at the targeted sensory cortex, as revealed by EEG and ESI analysis.