Journal Article

A high-performance speech neuroprosthesis

Avansino, Donald T., Wilson, Guy H., Kamdar, Foram, Kunz, Erin M., Hochberg, Leigh R., Druckmann, Shaul, Fan, Chaofei, Willett, Francis R., Glasser, Matthew F., Shenoy, Krishna V., Choi, Eun Young, Henderson, Jaimie M.

2023

Overview

Speech brain–computer interfaces (BCIs) have the potential to restore rapid communication to people with paralysis by decoding neural activity evoked by attempted speech into text 1 , 2 or sound 3 , 4 . Early demonstrations, although promising, have not yet achieved accuracies sufficiently high for communication of unconstrained sentences from a large vocabulary 1 – 7 . Here we demonstrate a speech-to-text BCI that records spiking activity from intracortical microelectrode arrays. Enabled by these high-resolution recordings, our study participant—who can no longer speak intelligibly owing to amyotrophic lateral sclerosis—achieved a 9.1% word error rate on a 50-word vocabulary (2.7 times fewer errors than the previous state-of-the-art speech BCI 2 ) and a 23.8% word error rate on a 125,000-word vocabulary (the first successful demonstration, to our knowledge, of large-vocabulary decoding). Our participant’s attempted speech was decoded  at 62 words per minute, which is 3.4 times as fast as the previous record 8 and begins to approach the speed of natural conversation (160 words per minute 9 ). Finally, we highlight two aspects of the neural code for speech that are encouraging for speech BCIs: spatially intermixed tuning to speech articulators that makes accurate decoding possible from only a small region of cortex, and a detailed articulatory representation of phonemes that persists years after paralysis. These results show a feasible path forward for restoring rapid communication to people with paralysis who can no longer speak. A speech-to-text brain–computer interface that records spiking activity from intracortical microelectrode arrays enabled an individual who cannot speak intelligibly to achieve 9.1 and 23.8% word error rates on a 50- and 125,000-word vocabulary, respectively.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 631/378/116/2394 / 631/378/2632/2634 / Accuracy / Amyotrophic lateral sclerosis / Amyotrophic Lateral Sclerosis - physiopathology / Amyotrophic Lateral Sclerosis - rehabilitation / Arrays / Brain-Computer Interfaces / Cerebral Cortex - physiology / Communication / Decoding / Electrodes / Firing pattern / Human-computer interface / Humanities and Social Sciences / Humans / Language / Microelectrodes / multidisciplinary / Neural Prostheses / Paralysis / Paralysis - physiopathology / Paralysis - rehabilitation / Prosthetics / Real time / Science / Science (multidisciplinary) / Sentences / Speaking / Speech / Speech recognition / Vocabulary / Words (language)