Dr. Jaimie Henderson and his team at Stanford Medicine are working on developing brain implants, called neuroprostheses, that can potentially help people with paralysis or speech impairments communicate. Two studies published in Nature describe how these implants can record a person’s neural activity as they attempt to speak, and then decode that activity into words displayed on a computer screen, audio speech, or even through an animated avatar.
Dr. Henderson’s personal experience of his father’s inability to communicate due to paralysis motivated his interest in this field. The studies detail their work with patients who had lost their ability to speak due to conditions like amyotrophic lateral sclerosis (ALS) or paralysis caused by a stroke.
In one study, electrodes were implanted in the brain of a patient with ALS. The patient attempted to speak, and the neural activity was decoded into words displayed on a screen. The system achieved a word error rate of around 23% with a 125,000-word vocabulary.
Another study involved a patient paralyzed by a stroke. An electrode device was implanted, which decoded neural activity into text on a screen. The system reached a median rate of 78 words per minute with a word error rate of 25%. Additionally, the patient’s attempted facial movements were synthesized into speech sounds, and an animated avatar was created to accompany the synthesized speech. Both studies highlight the potential for these neuroprostheses to significantly improve communication for individuals with severe speech impairments. The results are seen as a milestone in the field, with hopes for continued improvement and practical applications in the future. However, the researchers emphasize that these studies are proof of concept and more research is needed before clinical use can be considered. Despite this, there is optimism that such technology could ultimately help restore communication for people who have lost their ability to speak.