Researchers integrate transcranial focused ultrasound with brain-computer interface (BCI) to precisely target parts of the brain and enhance BCI performance.
BCI technology allows individuals with paralysis to control devices, including robotic arms and virtual keyboards, with their mind. While noninvasive BCI technologies are groundbreaking, many are characterized by high error rates and may benefit from improvement, before they can be widely used in clinical settings. Bin He and his lab at Carnegie Mellon University have been testing the ability of an emerging technology called low-intensity transcranial focused ultrasound (tFUS), to improve the accuracy rate of BCI technology. Results of this study were published in Nature Communications.
tFUS is a noninvasive device that can stimulate deep brain regions with high precision. Similar devices have limited specificity, which may result in brain stimulation outside of the intended area. tFUS, on the other hand, has high specificity, with a precision on the order of millimeters. Previous research has shown that tFUS can modulate brain signals during stimulation. However, tFUS stimulation has not previously been used to modulate brain signals in BCI.
In this study, healthy volunteers used a noninvasive BCI to type specific sequences of letters. Participants wore an electroencephalograph (EEG) cap for measuring brain activity while they typed on a virtual keyboard on a screen by staring at specific letters. Participants also received low-intensity focused ultrasound stimulation in the V5 brain region — the primary area associated with visual motion processing — or one of three control conditions. The focused ultrasound stimulation was administered just before and during the appearance of keyboard rows on the screen. All participants received all four experimental conditions.
The researchers found that V5-targeted stimulation using tFUS enhanced the performance of BCI, significantly reducing typing errors when compared with baseline conditions. Data analysis of the EEG readings showed that tFUS stimulation increased neural activity related to attention state, within the V5 area and in the downstream visual processing pathway. This suggests that focused V5 ultrasound improves BCI performance by increasing the brain’s attention to visual motion.
The enhanced performance observed in this study demonstrates the promise of emerging Neurotechnologies and begins to uncover potential biological mechanisms that can be targeted to improve the lives of individuals with paralysis and other impairments.
Reference
Kosnoff, J., Yu, K., Liu, C. et al. Transcranial focused ultrasound to V5 enhances human visual motion brain-computer interface by modulating feature-based attention. Nat Commun 15, 4382 (2024). https://doi.org/10.1038/s41467-024-48576-8