CharMark: Character-Level Markov Modeling to Detect Linguistic Signs of Dementia

CharMark: Character-Level Markov Modeling to Detect Linguistic Signs of Dementia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article CharMark: Character-Level Markov Modeling to Detect Linguistic Signs of Dementia Kevin Mekulu, Faisal Aqlan, Hui Yang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6391300/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Dementia, one of the most prevalent neurodegenerative diseases, affects millions worldwide. Understanding linguistic markers of dementia is crucial for elucidating how cognitive decline manifests in speech patterns. Current non-invasive assessments like the Montreal Cognitive Assessment (MoCA) and Saint Louis University Mental Status (SLUMS) tests rely on manual interpretation and lack detailed linguistic insights. This paper introduces a first-of-its-kind interpretable artificial intelligence (IAI) framework leveraging first-order Markov Chain models to characterize linguistic patterns associated with early-stage dementia. By computing steady-state probabilities for characters in speech transcripts from dementia subjects and healthy controls, we identified distinctive character-usage patterns. The space character " ", representing pauses, and letters such as "n" and "i", showed significant differences between groups. Principal Component Analysis (PCA) visualizations highlighted natural clustering corresponding to cognitive status. Kolmogorov-Smirnov tests confirmed statistically significant distributional differences in character usage between groups. Additionally, a Lasso Logistic Regression validated the relevance of these linguistic markers. Our primary contribution remains the identification and characterization of specific character-level linguistic patterns associated with cognitive decline. These findings demonstrate the potential of character-level modeling for detecting subtle language changes linked to dementia, informing the future development of sensitive cognitive screening tools. Biological sciences/Computational biology and bioinformatics/Computational neuroscience/Dynamical systems Biological sciences/Computational biology and bioinformatics/Computational neuroscience/Network models Health sciences/Biomarkers/Predictive markers Health sciences/Diseases/Neurological disorders/Dementia/Alzheimers disease Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6391300","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":449456696,"identity":"2573a41b-94a0-42f2-bf42-0b1abfb9c486","order_by":0,"name":"Kevin Mekulu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAx0lEQVRIiWNgGAWjYBACCQYG9g8fKtjkIFw24rSwMc44w2dMmhZm3ja5xAaitUjOyE57zMNmlr6d/4wBw4eyw4S1SPOc3W44hyctd+eMHAPGGeeI0CLH3rtB4o3EsdwNN3gMgC4kRgsz7wYJHoP/6Qbnzxgw/yVGizR77zZJngS2BIMDOQbMjMRokew5u9lwxgE2w50z0goO9pxLJ6xF4kbuxgcf/7HJm/Mf3vjgR5k1YS1wYADEB0hQD9UyCkbBKBgFowArAADryzpYJ+1miAAAAABJRU5ErkJggg==","orcid":"","institution":"Pennsylvania State University","correspondingAuthor":true,"prefix":"","firstName":"Kevin","middleName":"","lastName":"Mekulu","suffix":""},{"id":449456697,"identity":"6003626b-1e39-4c0e-98fa-3046a287b76a","order_by":1,"name":"Faisal Aqlan","email":"","orcid":"","institution":"University of Louisville","correspondingAuthor":false,"prefix":"","firstName":"Faisal","middleName":"","lastName":"Aqlan","suffix":""},{"id":449456698,"identity":"36d27857-6d45-45f7-91f2-1147314df742","order_by":2,"name":"Hui Yang","email":"","orcid":"","institution":"Pennsylvania State University","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Yang","suffix":""}],"badges":[],"createdAt":"2025-04-07 07:23:40","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6391300/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6391300/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":83808271,"identity":"cd83de14-2d9a-46aa-a6dd-5616f8795712","added_by":"auto","created_at":"2025-06-03 06:02:47","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":717548,"visible":true,"origin":"","legend":"","description":"","filename":"CharMarkCharacterLevelMarkovModelingtoDetectLinguisticSignsofDementiaRevised.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6391300/v1_covered_f7b5c937-4f33-44b7-91eb-c3578da25206.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"CharMark: Character-Level Markov Modeling to Detect Linguistic Signs of Dementia","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6391300/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6391300/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Dementia, one of the most prevalent neurodegenerative diseases, affects millions worldwide. 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