Cited by 582EEG and Brain-Computer InterfacesNeuroscience and Neural EngineeringTactile and Sensory Interactions

Neuroprosthesis for Decoding Speech in a Paralyzed Person with Anarthria

Open access
Moses, David A., Metzger, Sean L., Liu, Jessie R., Anumanchipalli, Gopala K., Makin, Joseph G., Sun, Pengfei F., Chartier, Josh, Dougherty, Maximilian E. +5 more·2021·New England Journal of Medicine

Abstract

BACKGROUND: Technology to restore the ability to communicate in paralyzed persons who cannot speak has the potential to improve autonomy and quality of life. An approach that decodes words and sentences directly from the cerebral cortical activity of such patients may represent an advancement over existing methods for assisted communication. METHODS: We implanted a subdural, high-density, multielectrode array over the area of the sensorimotor cortex that controls speech in a person with anarthria (the loss of the ability to articulate speech) and spastic quadriparesis caused by a brain-stem stroke. Over the course of 48 sessions, we recorded 22 hours of cortical activity while the participant attempted to say individual words from a vocabulary set of 50 words. We used deep-learning algorithms to create computational models for the detection and classification of words from patterns in the recorded cortical activity. We applied these computational models, as well as a natural-language model that yielded next-word probabilities given the preceding words in a sequence, to decode full sentences as the participant attempted to say them. RESULTS: We decoded sentences from the participant's cortical activity in real time at a median rate of 15.2 words per minute, with a median word error rate of 25.6%. In post hoc analyses, we detected 98% of the attempts by the participant to produce individual words, and we classified words with 47.1% accuracy using cortical signals that were stable throughout the 81-week study period. CONCLUSIONS: In a person with anarthria and spastic quadriparesis caused by a brain-stem stroke, words and sentences were decoded directly from cortical activity during attempted speech with the use of deep-learning models and a natural-language model. (Funded by Facebook and others; ClinicalTrials.gov number, NCT03698149.).

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1056/nejmoa2027540

Cites

39 of 39 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Speech neuroprostheses could restore communication for people with paralysis, but naturalistic speed and expressivity have not yet been achieved.

    “Speech neuroprostheses have the potential to restore communication to people living with paralysis, but naturalistic speed and expressivity are elusive1.”

    From A high-performance neuroprosthesis for speech decoding and avatar control (2023) · cites this paper as [1]

    The Background says decoding words and sentences from cortical activity could restore communication for paralyzed people who cannot speak. The Results report a median decoding rate of 15.2 words per minute, and the Methods describe a restricted 50-word set, supporting the point that this system had not achieved naturalistic communication. The paper does not assess speech expressivity or establish that expressivity remains elusive across speech neuroprostheses. (LLM, conf=0.83)

    Experimental — accuracy not yet measured
  • During 14 days of data collection shortly after implantation, text decoding performance exceeded previous BCIs' communication speeds by a factor of 4 or more.

    “During 14 days of data collection shortly after device implantation, we achieved high-performance text decoding, exceeding communication speeds of previous BCIs by a factor of 4 or more1,3,9”

    From A high-performance neuroprosthesis for speech decoding and avatar control (2023) · cites this paper as [1]

    The Results (Sentence Decoding; page unavailable) report real-time decoding at a median 15.2 words per minute, supporting the text-decoding portion of the claim. The Methods (Word and Sentence Task Design; page unavailable) describe 50 sessions over 81 weeks, not 14 days shortly after implantation. Our copy does not report a fourfold speed advantage over previous BCIs. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • The vocabulary size was expanded by a factor of 20 relative to the previous direct-speech BCI.

    “expanding the vocabulary size of our previous direct-speech BCI by a factor of 20 (ref. 1).”

    From A high-performance neuroprosthesis for speech decoding and avatar control (2023) · cites this paper as [1]

    The Methods (Word and Sentence Task Design; page unavailable) identify the cited direct-speech BCI as using a 50-word set. The paper does not report a subsequent vocabulary expansion or establish the claimed factor of 20. (LLM, conf=0.84)

    Experimental — accuracy not yet measured
  • Demonstrations in able speakers with epilepsy served as proof-of-principle for future applications in individuals with vocal-tract paralysis that led to the first clinical trial for a speech neuroprosthesis using a chronically implanted 128-electrode ECoG array.

    “Importantly, those demonstrations in able speakers with epilepsy served as a proof-of-principle for future applications in individuals with vocal-tract paralysis that led to the first clinical trial for a speech neuroprosthesis using a chronically implanted 128-electrode ECoG array12.”

    From The speech neuroprosthesis (2024) · cites this paper as [12]

    Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured
  • As a first approach to counter a lack of alignment, Moses et al. instructed a participant with anarthria to attempt to speak sentences word-by-word.

    “As a first approach to counter a lack of alignment between neural activity and ground-truth targets, Moses et al.12 instructed a participant with anarthria to attempt to speak sentences word-by-word (with pauses between words).”

    From The speech neuroprosthesis (2024) · cites this paper as [12]

    The Methods (Word and Sentence Task Design; page not supplied) say the participant with anarthria attempted the words of each sentence in order. The Discussion identifies a time-alignment problem, but the Methods do not say he was instructed to pause between words; they say he attempted them at the fastest speed he could perform comfortably. (LLM, conf=0.85)

    Experimental — accuracy not yet measured

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 3

  1. [2]Nip I, Roth CR. Anarthria. In: Kreutzer J, DeLuca J, Caplan B, eds. Encyclopedia of clinical neuropsychology. 2nd ed. New York: Springer International Publishing, 2017: 1.
  2. [11]Guenther FH, Hickok G. Neural models of motor speech control. In: Hickok G, Small S, eds. Neurobiology of language. Cambridge, MA: Academic Press, 2015: 725– 40.
  3. [27]Simonyan K, Vedaldi A, Zisserman A. Deep inside convolutional networks: visualising image classification models and saliency maps. In: Bengio Y, LeCun Y, eds. Workshop at the International Conference on Learning Representations. Banff, AB, Canada: ICLR Workshop, 2014.

Cited by

Sorted by citations

Authors
Moses, D. A., Metzger, S. L., Liu, J. R., Anumanchipalli, G. K., Makin, J. G., Sun, P. F., Chartier, J., Dougherty, M. E., Liu, P. M., Abrams, G. M., Tu-Chan, A., Ganguly, K., & Chang, E. F.
Affiliations
University of California, San Francisco (US)
Venue
New England Journal of Medicine
Published
2021-07-15
Volume
385
Issue
3
Pages
217-227
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
OpenAlex
W3180220247
Cited by
582
References
39
Citations by year
2026: 105 · 2025: 127 · 2024: 123 · 2023: 114 · 2022: 77 · 2021: 34 · 2019: 2
FWCI
45.77
Type
journal article
Language
en
Open access
Locations
  • New England Journal of Medicine (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • eScholarship (California Digital Library) (submittedVersion)
Funders
  • Facebook (Sponsored Academic Research Agreement)
  • National Institutes of Health (U01 NS098971-01)
  • William K. Bowes, Jr. Foundation
  • Howard Hughes Medical Institute
  • Shurl and Kay Curci Foundation
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › EEG and Brain-Computer Interfaces
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neural Engineering
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Tactile and Sensory Interactions
Keywords
neural prostheses, speech decoding, anarthria, paralysis, brain-computer interface, sensorimotor cortex, deep learning, natural language models, brainstem infarction, spastic quadriplegia, word error rate
MeSH terms
Electrocorticography, Deep Learning, Adult, Dysarthria, Electrodes, Implanted, Humans, Male, Natural Language Processing, Quadriplegia, Speech, Brain Stem Infarctions, Neural Prostheses, Brain-Computer Interfaces, Sensorimotor Cortex

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review