Brain Implant Revolutionizes Life for ALS Patient
WHO:
Nature - Casey Harrell, a 48-year-old study participant diagnosed with amyotrophic lateral sclerosis (ALS).
Nature - Sergey Stavisky, a neuroscientist at the University of California, Davis, co-author of the study.
Nature - Christian Herff, a computational neuroscientist at Maastricht University in the Netherlands.
Nature - Nicholas Card, a neural engineer at the University of California, Davis, co-author of the study.
WHAT:
Nature - The study analyzed Harrell’s home use of the BCI for nearly two years, making it “the most extensive data set and the longest-running speech communication of anyone” with such an implant, according to co-author Sergey Stavisky.
Nature - Harrell communicated 183,060 sentences, with 92% labeled as mostly correct, and the BCI also picked up neural signals for attempted hand movements to control a computer mouse.
Nature - The information transfer rate of the BCI is “several orders of magnitude faster” than previous efforts to deploy BCIs at patients’ homes, as stated by Christian Herff.
Nature - A brain-computer interface (BCI) has enabled Harrell to communicate at an average speed of 56 words per minute.
Nature - Harrell communicated 183,060 sentences using the BCI, with 92% labeled as mostly correct.
The Washington Post - Harrell's life has been impacted by ALS for six years, leading to a significant reduction in his ability to communicate.
Nature - The study reported that Harrell used the BCI at home on 364 of 397 days.
WHERE:
Nature - Harrell is based in Oakland, California.
Nature - The study was conducted at the University of California, Davis.
WHEN:
Nature - The study was published in Nature Medicine on June 15.
Nature - Harrell had 256 microelectrodes implanted in 2023.
WHY:
Nature - The BCI allows Harrell to communicate and maintain his job in climate advocacy, providing financial support and insurance for his family.
Nature - The study aims to demonstrate the effectiveness of BCIs in improving the daily lives of patients with motor neuron diseases.
HOW:
Nature - The BCI system was trained with the help of researchers, and Harrell began using it independently after approximately 40 weeks, continuing to use it today.
Nature - The BCI translates neural activity into text displayed on a computer screen, allowing Harrell to send messages and operate a computer.
Nature - The BCI system was trained with the help of researchers, and Harrell began using it independently after approximately 40 weeks.
Nature - The BCI includes a text-to-speech system that uses a synthesized version of Harrell's voice from before his diagnosis.
Nature - The system features an optional 'privacy mode' to prevent data transmission to researchers.
(UPDATED June 16, 2026 12:38 UTC)
A groundbreaking study published in Nature reveals that a man named Harrell has communicated an impressive 183,060 sentences using a brain-computer interface, or BCI, over nearly two years, making this the most extensive data set of its kind. Co-author Sergey Stavisky noted that 92% of these sentences were labeled as mostly correct, while the BCI also detected neural signals for attempted hand movements to control a computer mouse. The research highlights that the information transfer rate of this BCI is “several orders of magnitude faster” than previous home deployments, with Harrell having trained on the system for about 40 weeks before using it independently.
--
(UPDATED June 16, 2026 04:26 UTC)
A groundbreaking study published in Nature Medicine reveals that a brain-computer interface has enabled Casey Harrell, a 48-year-old participant diagnosed with ALS, to communicate at an impressive average speed of 56 words per minute. Over the course of the study, Harrell communicated 183,060 sentences, with 92% deemed mostly correct, allowing him to maintain his job in climate advocacy and support his family. The system, developed by researchers at the University of California, Davis, translates Harrell's neural activity into text and includes a text-to-speech feature that uses a synthesized version of his voice from before his diagnosis.