{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,3]],"date-time":"2026-11-03T07:58:32Z","timestamp":1793692712338,"version":"4.5.1"},"reference-count":35,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,8,3]],"date-time":"2022-08-03T00:00:00Z","timestamp":1659484800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Hum. Neurosci."],"abstract":"<jats:p>The motivation of someone who is locked-in, that is, paralyzed and mute, is to find relief for their loss of function. The data presented in this report is part of an attempt to restore one of those lost functions, namely, speech. An essential feature of the development of a speech prosthesis is optimal decoding of patterns of recorded neural signals during <jats:italic>silent or covert<\/jats:italic> speech, that is, speaking \u201cinside the head\u201d with output that is inaudible due to the paralysis of the articulators. The aim of this paper is to illustrate the importance of both fast and slow single unit firings recorded from an individual with locked-in syndrome and from an intact participant <jats:italic>speaking silently<\/jats:italic>. Long duration electrodes were implanted in the motor speech cortex for up to 13 years in the locked-in participant. The data herein provide evidence that slow firing single units are essential for <jats:italic>optimal decoding accuracy<\/jats:italic>. Additional evidence indicates that slow firing single units can be <jats:italic>conditioned<\/jats:italic> in the locked-in participant 5 years after implantation, further supporting their role in decoding.<\/jats:p>","DOI":"10.3389\/fnhum.2022.874199","type":"journal-article","created":{"date-parts":[[2022,8,3]],"date-time":"2022-08-03T12:30:07Z","timestamp":1659529807000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Slow Firing Single Units Are Essential for Optimal Decoding of Silent Speech"],"prefix":"10.3389","volume":"16","author":[{"given":"Ananya","family":"Ganesh","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andre J.","family":"Cervantes","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philip R.","family":"Kennedy","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,8,3]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"1022","DOI":"10.1109\/EMBC.2017.8037000","article-title":"EEG-based classification of bilingual unspoken speech using ANN","volume":"7","author":"Balaji","year":"2017","journal-title":"Conf. Proc. IEEE Eng. Med. Biol. Soc"},{"key":"B2","doi-asserted-by":"publisher","first-page":"168","DOI":"10.1016\/j.jneumeth.2008.06.030","article-title":"Neurotrophic electrode: method of assembly and implantation into human motor speech cortex","volume":"174","author":"Bartels","year":"2008","journal-title":"J. Neurosci. Methods"},{"key":"B3","doi-asserted-by":"publisher","first-page":"657","DOI":"10.1038\/nature26147","article-title":"Moving magnetoencephalography towards real-world applications with a wearable system","volume":"555","author":"Boto","year":"2018","journal-title":"Nature"},{"key":"B4","doi-asserted-by":"publisher","first-page":"247","DOI":"10.1038\/nature17435","article-title":"Restoring cortical control of functional movement in a human with quadriplegia","volume":"533","author":"Bouton","year":"2016","journal-title":"Nature"},{"key":"B5","doi-asserted-by":"publisher","first-page":"367","DOI":"10.1016\/j.specom.2010.01.001","article-title":"Brain-computer interfaces for speech communication","volume":"52","author":"Brumberg","year":"2010","journal-title":"Speech Commun"},{"key":"B6","doi-asserted-by":"publisher","first-page":"65","DOI":"10.3389\/fnins.2011.00065","article-title":"Classification of intended phoneme production from chronic intracortical microelectrode recordings in speech motor cortex","volume":"5","author":"Brumberg","year":"2011","journal-title":"Front. Neurosci."},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.1002593","article-title":"Brain-computer interface-based communication in the completely locked-in state","author":"Chaudhary","year":"2017","journal-title":"PLoS Biol"},{"key":"B8","doi-asserted-by":"publisher","first-page":"557","DOI":"10.1016\/S0140-6736(12)61816-9","article-title":"High-performance neuroprosthesis control by an individual with tetraplegia","volume":"381","author":"Collinger","year":"2013","journal-title":"Lancet"},{"key":"B9","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1016\/j.conb.2013.08.015","article-title":"Speech map in the human ventral sensory-motor cortex","volume":"24","author":"Conant","year":"2014","journal-title":"Curr. Opin. Neurobiol"},{"key":"B10","doi-asserted-by":"publisher","first-page":"290","DOI":"10.3389\/fnins.2020.00290","article-title":"Decoding imagined and spoken phrases from non-invasive neural (MEG) signals","volume":"14","author":"Dash","year":"","journal-title":"Front. Neurosci."},{"key":"B11","doi-asserted-by":"publisher","first-page":"182320","DOI":"10.1109\/ACCESS.2020.3028831","article-title":"MEG sensor selection for neural speech decoding","volume":"8","author":"Dash","year":"","journal-title":"IEEE Access"},{"key":"B12","doi-asserted-by":"publisher","first-page":"046019","DOI":"10.1088\/1741-2560\/13\/4\/046019","article-title":"Histological evaluation of a chronically-implanted electrocorticographic electrode grid in a non-human primate","volume":"13","author":"Degenhart","year":"2016","journal-title":"J. Neural Eng."},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1088\/1741-2552\/aab7a0","article-title":"Intracortical recording stability in human brain-computer interface users","author":"Downey","year":"2018","journal-title":"J. Neural Eng"},{"key":"B14","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/s41598-017-08120-9","article-title":"Neuroprosthetic-enabled control of graded arm muscle contraction in a paralyzed human","volume":"7","author":"Friedenberg","year":"2017","journal-title":"Sci. Rep."},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.3389\/fnhum.2020.00111","article-title":"Histological confirmation of myelinated neural filaments within the tip of the Neurotrophic Electrode after a decade of neural recordings","author":"Gearin","year":"2020","journal-title":"Front. Hum. Neurosci"},{"key":"B16","doi-asserted-by":"publisher","first-page":"e8218","DOI":"10.1371\/journal.pone.0008218","article-title":"A wireless brain-machine interface for real-time speech synthesis","volume":"4","author":"Guenther","year":"2009","journal-title":"PLoS ONE"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.3389\/fnins.2020.00123","article-title":"The potential of stereotaxic-EEG for brain-computer interfaces: current progress and future directions","author":"Herff","year":"2020","journal-title":"Front. Neurosci"},{"key":"B18","doi-asserted-by":"publisher","first-page":"372","DOI":"10.1038\/nature11076","article-title":"Reach and grasp by people with tetraplegia using a neurally controlled robotic arm","volume":"485","author":"Hochberg","year":"2012","journal-title":"Nature"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1038\/s42003-020-01484-1","article-title":"The human primary somatosensory cortex encodes imagined movement in the absence of sensory information","author":"Jafari","year":"2020","journal-title":"Commun. Biol"},{"key":"B20","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/B978-0-444-53815-4.00020-0","article-title":"Making the lifetime connection between brain and machine for restoring and enhancing function","volume":"194","author":"Kennedy","year":"2011","journal-title":"Proc. Brain Res."},{"key":"B21","doi-asserted-by":"publisher","first-page":"381","DOI":"10.1080\/13554794.2010.532137","article-title":"Changes in emotional state modulate neuronal firing rates of human speech motor cortex: a case study in long-term recording","volume":"17","author":"Kennedy","year":"2011","journal-title":"Neurocase"},{"key":"B22","first-page":"31","article-title":"To invade or not to invade, that is the question for brain computer interfacing","volume":"12","author":"Kennedy","year":"2018","journal-title":"Curr. Trends Neurol."},{"key":"B23","article-title":"\u201cValidation of neurotrophic electrode long term recordings in human cortex,\u201d","volume-title":"Handbook of Biomedical Engineering","author":"Kennedy","year":"2018"},{"key":"B24","article-title":"\u201cAdvances in the development of a speech prosthesis,\u201d","volume-title":"Book Chapter in Brain-Machine Interfaces: Uses and Developments","author":"Kennedy","year":"2017"},{"key":"B25","doi-asserted-by":"publisher","first-page":"89","DOI":"10.1016\/0304-3940(92)90627-J","article-title":"The cone electrode: ultrastructural studies following long-term recording","volume":"142","author":"Kennedy","year":"1992","journal-title":"Neurosci. Lett."},{"key":"B26","doi-asserted-by":"publisher","first-page":"1741","DOI":"10.1088\/1741-2552\/aace8c","article-title":"EEGNet: a compact convolutional neural network for EEG-based brain\u2013computer interfaces","volume":"22","author":"Lawhern","year":"2018","journal-title":"J. Neural Eng"},{"key":"B27","doi-asserted-by":"publisher","first-page":"575","DOI":"10.1038\/s41593-020-0608-8","article-title":"Machine translation of cortical activity to text with an encoder-decoder framework","volume":"23","author":"Makin","year":"2020","journal-title":"Nat. Neurosci"},{"key":"B28","doi-asserted-by":"publisher","first-page":"217","DOI":"10.1056\/NEJMoa2027540","article-title":"Neuroprosthesis for decoding speech in a paralyzed person with anarthria","volume":"385","author":"Moses","year":"2021","journal-title":"N. Engl J. Med"},{"key":"B29","doi-asserted-by":"publisher","first-page":"1","DOI":"10.2196\/16194","article-title":"An integrated brain-machine interface platform with thousands of channels","volume":"18","author":"Musk","year":"2019","journal-title":"BioRxiv"},{"key":"B30","doi-asserted-by":"publisher","first-page":"64","DOI":"10.1016\/j.conb.2017.12.010","article-title":"Recent advances in neural dust: towards a neural interface platform","volume":"50","author":"Neely","year":"2018","journal-title":"Curr. Opin. Neurobiol"},{"key":"B31","doi-asserted-by":"publisher","first-page":"1798","DOI":"10.1016\/j.clinph.2019.07.020","article-title":"Stability of a chronic implanted brain-computer interface in late-stage amyotrophic lateral sclerosis","volume":"130","author":"Pels","year":"2019","journal-title":"Clin. Neurophysiol."},{"key":"B32","doi-asserted-by":"publisher","first-page":"63","DOI":"10.15424\/bioelectronmed.2015.00010","article-title":"Time stability and coherence analysis of multiunit, single-unit and local field potential neuronal signals in chronically implanted brain electrodes","volume":"2","author":"Sharma","year":"2015","journal-title":"Bioelectron. Med."},{"key":"B33","doi-asserted-by":"publisher","first-page":"249","DOI":"10.1038\/s41586-021-03506-2","article-title":"High-performance brain-to-text communication via handwriting","volume":"593","author":"Willett","year":"2021","journal-title":"Nature"},{"key":"B34","doi-asserted-by":"publisher","first-page":"4415","DOI":"10.1523\/JNEUROSCI.3851-15.2016","article-title":"Theta rhythmic clock-like activity of participant in the mouse hippocampus","volume":"36","author":"Zhang","year":"2016","journal-title":"J. Neurosci."},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1088\/1741-2552\/ab05b6","article-title":"Parallel, minimally-invasive implantation of ultra-flexible neural electrode arrays","author":"Zhao","year":"2019","journal-title":"J. Neural Eng"}],"container-title":["Frontiers in Human Neuroscience"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnhum.2022.874199\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,8,3]],"date-time":"2022-08-03T12:30:13Z","timestamp":1659529813000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fnhum.2022.874199\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,3]]},"references-count":35,"alternative-id":["10.3389\/fnhum.2022.874199"],"URL":"https:\/\/doi.org\/10.3389\/fnhum.2022.874199","relation":{},"ISSN":["1662-5161"],"issn-type":[{"value":"1662-5161","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,3]]},"article-number":"874199"}}