{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,13]],"date-time":"2026-01-13T21:27:41Z","timestamp":1768339661288,"version":"3.49.0"},"reference-count":34,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2024,4,19]],"date-time":"2024-04-19T00:00:00Z","timestamp":1713484800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Portuguese Foundation for Science and Technology (FCT)","award":["ISR-UC UIDB\/00048\/2020"],"award-info":[{"award-number":["ISR-UC UIDB\/00048\/2020"]}]},{"name":"the Portuguese Foundation for Science and Technology (FCT)","award":["10.54499\/UIDB\/00048\/2020"],"award-info":[{"award-number":["10.54499\/UIDB\/00048\/2020"]}]},{"name":"the Portuguese Foundation for Science and Technology (FCT)","award":["PTDC\/EEI-AUT\/30935\/2017"],"award-info":[{"award-number":["PTDC\/EEI-AUT\/30935\/2017"]}]},{"name":"the Portuguese Foundation for Science and Technology (FCT)","award":["BCI4ALL2024"],"award-info":[{"award-number":["BCI4ALL2024"]}]},{"name":"the Portuguese Foundation for Science and Technology (FCT)","award":["2023.03995.BD"],"award-info":[{"award-number":["2023.03995.BD"]}]},{"name":"the Portuguese Foundation for Science and Technology (FCT)","award":["10.54499\/2023.03995.BD"],"award-info":[{"award-number":["10.54499\/2023.03995.BD"]}]},{"DOI":"10.13039\/501100001871","name":"B-RELIABLE","doi-asserted-by":"publisher","award":["ISR-UC UIDB\/00048\/2020"],"award-info":[{"award-number":["ISR-UC UIDB\/00048\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"B-RELIABLE","doi-asserted-by":"publisher","award":["10.54499\/UIDB\/00048\/2020"],"award-info":[{"award-number":["10.54499\/UIDB\/00048\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"B-RELIABLE","doi-asserted-by":"publisher","award":["PTDC\/EEI-AUT\/30935\/2017"],"award-info":[{"award-number":["PTDC\/EEI-AUT\/30935\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"B-RELIABLE","doi-asserted-by":"publisher","award":["BCI4ALL2024"],"award-info":[{"award-number":["BCI4ALL2024"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"B-RELIABLE","doi-asserted-by":"publisher","award":["2023.03995.BD"],"award-info":[{"award-number":["2023.03995.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"B-RELIABLE","doi-asserted-by":"publisher","award":["10.54499\/2023.03995.BD"],"award-info":[{"award-number":["10.54499\/2023.03995.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"the FCT Ph.D. scholarship","award":["ISR-UC UIDB\/00048\/2020"],"award-info":[{"award-number":["ISR-UC UIDB\/00048\/2020"]}]},{"name":"the FCT Ph.D. scholarship","award":["10.54499\/UIDB\/00048\/2020"],"award-info":[{"award-number":["10.54499\/UIDB\/00048\/2020"]}]},{"name":"the FCT Ph.D. scholarship","award":["PTDC\/EEI-AUT\/30935\/2017"],"award-info":[{"award-number":["PTDC\/EEI-AUT\/30935\/2017"]}]},{"name":"the FCT Ph.D. scholarship","award":["BCI4ALL2024"],"award-info":[{"award-number":["BCI4ALL2024"]}]},{"name":"the FCT Ph.D. scholarship","award":["2023.03995.BD"],"award-info":[{"award-number":["2023.03995.BD"]}]},{"name":"the FCT Ph.D. scholarship","award":["10.54499\/2023.03995.BD"],"award-info":[{"award-number":["10.54499\/2023.03995.BD"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Applied Sciences"],"abstract":"<jats:p>In a completely locked-in state (CLIS), often resulting from traumatic brain injury or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS), patients lose voluntary muscle control, including eye movement, making communication impossible. Brain-computer interfaces (BCIs) offer hope for restoring communication, but achieving reliable communication with these patients remains a challenge. This study details the design, testing, and comparison of nine visuo-auditory P300-based BCIs (combining different visual and auditory stimuli and different visual layouts) with a CLIS patient over ten months. The aim was to evaluate the impact of these stimuli in achieving effective communication. While some interfaces showed promising progress, achieving up to 90% online accuracy in one session, replicating this success in subsequent sessions proved challenging, with the average online accuracy across all sessions being 56.4 \u00b1 15.2%. The intertrial variability in EEG signals and the low discrimination between target and non-target events were the main challenge. Moreover, the lack of communication with the patient made BCI design a challenging blind trial-and-error process. Despite the inconsistency of the results, it was possible to infer that the combination of visual and auditory stimuli had a positive impact, and that there was an improvement over time.<\/jats:p>","DOI":"10.3390\/app14083464","type":"journal-article","created":{"date-parts":[[2024,4,19]],"date-time":"2024-04-19T10:53:17Z","timestamp":1713523997000},"page":"3464","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Comparing Several P300-Based Visuo-Auditory Brain-Computer Interfaces for a Completely Locked-in ALS Patient: A Longitudinal Case Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5966-2039","authenticated-orcid":false,"given":"Rute","family":"Bettencourt","sequence":"first","affiliation":[{"name":"Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4364-6373","authenticated-orcid":false,"given":"Miguel","family":"Castelo-Branco","sequence":"additional","affiliation":[{"name":"Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal"}]},{"given":"Edna","family":"Gon\u00e7alves","sequence":"additional","affiliation":[{"name":"University Hospital Center of S\u00e3o Jo\u00e3o, 4200-319 Porto, Portugal"},{"name":"Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7750-5221","authenticated-orcid":false,"given":"Urbano J.","family":"Nunes","sequence":"additional","affiliation":[{"name":"Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal"},{"name":"Department of Electrical and Computer Engineering, Faculty of Sciences and Technology, University of Coimbra, 3030-290 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9967-845X","authenticated-orcid":false,"given":"Gabriel","family":"Pires","sequence":"additional","affiliation":[{"name":"Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal"},{"name":"Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"Department of Engineering, School of Technology of Tomar, Polytechnic Institute of Tomar, 2300-313 Tomar, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"517","DOI":"10.1111\/j.1469-8986.2006.00456.x","article-title":"Breaking the Silence: Brain\u2013Computer Interfaces (BCI) for Communication and Motor Control","volume":"43","author":"Birbaumer","year":"2006","journal-title":"Psychophysiology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1007\/BF00313105","article-title":"Varieties of the Locked-in Syndrome","volume":"221","author":"Bauer","year":"1979","journal-title":"J. Neurol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"17562864231160872","DOI":"10.1177\/17562864231160873","article-title":"Locked-in Syndrome Revisited","volume":"16","author":"Schnetzer","year":"2023","journal-title":"Ther. Adv. Neurol. Disord."},{"key":"ref_4","first-page":"E938","article-title":"An Observational Study on Quality of Life and Preferences to Sustain Life in Locked-in State","volume":"93","author":"Andersen","year":"2019","journal-title":"Neurology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1080\/21678421.2017.1392576","article-title":"Usability of Eyetracking Computer Systems and Impact on Psychological Wellbeing in Patients with Advanced Amyotrophic Lateral Sclerosis","volume":"19","author":"Linse","year":"2018","journal-title":"Amyotroph. Lateral Scler. Front. Degener."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"16787","DOI":"10.1038\/s41598-018-35211-y","article-title":"Long-Term Use of a Neural Prosthesis in Progressive Paralysis","volume":"8","author":"Okahara","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"109661","DOI":"10.1016\/j.jneumeth.2022.109661","article-title":"Visuo-Auditory Stimuli with Semantic, Temporal and Spatial Congruence for a P300-Based BCI: An Exploratory Test with an ALS Patient in a Completely Locked-in State","volume":"379","author":"Pires","year":"2022","journal-title":"J. Neurosci. Methods"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"251","DOI":"10.3389\/fnins.2017.00251","article-title":"Complete Locked-in and Locked-in Patients: Command Following Assessment and Communication with Vibro-Tactile P300 and Motor Imagery Brain-Computer Interface Tools","volume":"11","author":"Guger","year":"2017","journal-title":"Front. Neurosci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1186\/s12984-019-0493-0","article-title":"Electroencephalography-Based Endogenous Brain-Computer Interface for Online Communication with a Completely Locked-in Patient","volume":"16","author":"Han","year":"2019","journal-title":"J. Neuroeng. Rehabil."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1093\/ietisy\/e90-d.7.1028","article-title":"A Communication Means for Totally Locked-in ALS Patients Based on Changes in Cerebral Blood Volume Measured with Near-Infrared Light","volume":"E90-D","author":"Masayoshi","year":"2007","journal-title":"IEICE Trans. Inf. Syst."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.bandl.2019.05.004","article-title":"Semantic and BCI-Performance in Completely Paralyzed Patients: Possibility of Language Attrition in Completely Locked in Syndrome","volume":"194","author":"Rana","year":"2019","journal-title":"Brain Lang."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1236","DOI":"10.1038\/s41467-022-28859-8","article-title":"Spelling Interface Using Intracortical Signals in a Completely Locked-in Patient Enabled via Auditory Neurofeedback Training","volume":"13","author":"Chaudhary","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Rezvani, S., Hosseini-Zahraei, S.H., Tootchi, A., Guger, C., Chaibakhsh, Y., Saberi, A., and Chaibakhsh, A. (2023). A Review on the Performance of Brain-Computer Interface Systems Used for Patients with Locked-in and Completely Locked-in Syndrome. Cogn. Neurodyn., 1\u201325.","DOI":"10.1007\/s11571-023-09995-3"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1111\/j.1749-6632.2008.04122.x","article-title":"A Brain\u2013Computer Interface Controlled Auditory Event-Related Potential (P300) Spelling System for Locked-In Patients","volume":"1157","author":"Furdea","year":"2009","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2658","DOI":"10.1016\/j.clinph.2008.06.019","article-title":"Brain\u2013Computer Interfaces and Communication in Paralysis: Extinction of Goal Directed Thinking in Completely Paralysed Patients?","volume":"119","author":"Birbaumer","year":"2008","journal-title":"Clin. Neurophysiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"925","DOI":"10.1016\/j.clinph.2010.08.019","article-title":"Transition from the Locked in to the Completely Locked-in State: A Physiological Analysis","volume":"122","author":"Murguialday","year":"2011","journal-title":"Clin. Neurophysiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e258","DOI":"10.1212\/WNL.0000000000005812","article-title":"Independent Home Use of a Brain-Computer Interface by People with Amyotrophic Lateral Sclerosis","volume":"91","author":"Wolpaw","year":"2018","journal-title":"Neurology"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1163\/156856897X00357","article-title":"The Psychophysics Toolbox","volume":"10","author":"Brainard","year":"1997","journal-title":"Spat. Vis."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1163\/156856897X00366","article-title":"The VideoToolbox Software for Visual Psychophysics: Transforming Numbers into Movies","volume":"10","author":"Pelli","year":"1997","journal-title":"Spat. Vis."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1377","DOI":"10.1080\/02699930903485076","article-title":"Presentation and validation of the Radboud faces database","volume":"24","author":"Langner","year":"2010","journal-title":"Cogn. Emotion"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"56016","DOI":"10.1088\/1741-2560\/8\/5\/056016","article-title":"Flashing Characters with Famous Faces Improves ERP-Based Brain-Computer Interface Performance","volume":"8","author":"Kaufmann","year":"2011","journal-title":"J. Neural Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"893","DOI":"10.1016\/j.clinph.2012.11.006","article-title":"Face Stimuli Effectively Prevent Brain\u2013Computer Interface Inefficiency in Patients with Neurodegenerative Disease","volume":"124","author":"Kaufmann","year":"2013","journal-title":"Clin. Neurophysiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"026018","DOI":"10.1088\/1741-2560\/9\/2\/026018","article-title":"A Novel BCI Based on ERP Components Sensitive to Configural Processing of Human Faces","volume":"9","author":"Zhang","year":"2012","journal-title":"J. Neural Eng."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.jneumeth.2015.11.026","article-title":"Toward a Reliable Gaze-Independent Hybrid BCI Combining Visual and Natural Auditory Stimuli","volume":"261","author":"Barbosa","year":"2016","journal-title":"J. Neurosci. Methods"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1016\/j.jneumeth.2010.11.016","article-title":"Statistical Spatial Filtering for a P300-Based BCI: Tests in Able-Bodied, and Patients with Cerebral Palsy and Amyotrophic Lateral Sclerosis","volume":"195","author":"Pires","year":"2011","journal-title":"J. Neurosci. Methods"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.jneumeth.2003.10.009","article-title":"EEGLAB: An Open Source Toolbox for Analysis of Single-Trial EEG Dynamics Including Independent Component Analysis","volume":"134","author":"Delorme","year":"2004","journal-title":"J. Neurosci. Methods"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"514361","DOI":"10.1155\/2015\/514361","article-title":"Brain Signals of Face Processing as Revealed by Event-Related Potentials","volume":"2015","author":"Olivares","year":"2015","journal-title":"Behav. Neurol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.neucom.2021.10.078","article-title":"Spatial Filtering Based on Riemannian Distance to Improve the Generalization of ErrP Classification","volume":"470","author":"Cruz","year":"2022","journal-title":"Neurocomputing"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1064","DOI":"10.1016\/j.clinph.2021.01.013","article-title":"Neurophysiological Aspects of the Completely Locked-in Syndrome in Patients with Advanced Amyotrophic Lateral Sclerosis","volume":"132","author":"Wu","year":"2021","journal-title":"Clin. Neurophysiol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"026006","DOI":"10.1088\/1741-2560\/11\/2\/026006","article-title":"Assessing Attention and Cognitive Function in Completely Locked-in State with Event-Related Brain Potentials and Epidural Electrocorticography","volume":"11","author":"Bensch","year":"2014","journal-title":"J. Neural Eng."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.neures.2020.01.013","article-title":"Electroencephalography of Completely Locked-in State Patients with Amyotrophic Lateral Sclerosis","volume":"162","author":"Maruyama","year":"2021","journal-title":"Neurosci. Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1007\/s11571-020-09639-w","article-title":"EEG Power Spectral Density in Locked-in and Completely Locked-in State Patients: A Longitudinal Study","volume":"15","author":"Secco","year":"2021","journal-title":"Cogn. Neurodyn."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"046085","DOI":"10.1088\/1741-2552\/ac0488","article-title":"Online Control of an Assistive Active Glove by Slow Cortical Signals in Patients with Amyotrophic Lateral Sclerosis","volume":"18","author":"Aliakbaryhosseinabadi","year":"2021","journal-title":"J. Neural Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"056023","DOI":"10.1088\/1741-2552\/ac15e3","article-title":"Participant-Specific Classifier Tuning Increases the Performance of Hand Movement Detection from EEG in Patients with Amyotrophic Lateral Sclerosis","volume":"18","author":"Aliakbaryhosseinabadi","year":"2021","journal-title":"J. Neural Eng."}],"container-title":["Applied Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3417\/14\/8\/3464\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:31:16Z","timestamp":1760106676000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3417\/14\/8\/3464"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,19]]},"references-count":34,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2024,4]]}},"alternative-id":["app14083464"],"URL":"https:\/\/doi.org\/10.3390\/app14083464","relation":{},"ISSN":["2076-3417"],"issn-type":[{"value":"2076-3417","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,19]]}}}