{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:19:18Z","timestamp":1792790358054,"version":"4.5.0"},"posted":{"date-parts":[[2026,9,20]]},"group-title":"Psychiatry and Clinical Psychology","reference-count":50,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T00:00:00Z","timestamp":1789862400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.medrxiv.org\/about\/FAQ#license"}],"funder":[{"name":"National Center for Advancing Translational Sciences of the National Institutes of Health","award":["K12TR004788-01A1"],"award-info":[{"award-number":["K12TR004788-01A1"]}],"id":[{"id":"https:\/\/ror.org\/04pw6fb54","id-type":"ROR","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/040may582","id-type":"ROR","asserted-by":"publisher"}]},{"name":"The Rutgers-Princeton Center for Computational Cognitive Neuropsychiatry"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,9,20]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Objective<\/jats:title>\n                  <jats:p>Child and early adolescent onset psychosis (COP) is associated with subtle changes in language linked to thought disorder, a key contributor to functional impairment. Large language models (LLM) can detect deviations from expected language patterns by jointly analyzing sentence structure and word choice. This integrated information is captured by measures such as (pseudo)-perplexity, which quantify how difficult it is for an LLM to predict individual words given the surrounding linguistic context. The objective was to determine if perplexity measures change with age and whether they are altered in COP.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Method<\/jats:title>\n                  <jats:p>This study tested for a difference in perplexity in COP cases (N = 23) mean age 12.78 years as compared to controls (N = 15) mean age 11.67 years. Extensive manually transcribed interviews were analyzed (controls: 3,829; cases: 6,579 mean words).<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Perplexity derived from Large Language Model Meta AI (LLaMA) had a significant negative correlation with age in cases but not in controls. Pseudo-perplexity derived from Bidirectional Encoder Representations from Transformers (BERT) did not have a significant correlation with age in either group. Group differences were evaluated using generalized linear models with (pseudo)-perplexity as the dependent variable, case status as the predictor and age and number of words as covariates. The model predicting perplexity was significant and case status significantly predicted perplexity. In contrast, the model predicting pseudo-perplexity was not significant.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>These differences in perplexity are interpreted as reflecting an altered developmental trajectory in the real-time semantic and syntactic planning that directs the flow of language in individuals with COP.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Plain language summary<\/jats:title>\n                  <jats:p>Childhood onset psychosis (COP) is difficult to detect with subtle changes in language that impair communication and functioning. We used large language models (LLMs) to detect developmental changes in language in COP and controls. LLMs found language in COP harder to predict with improved prediction with increasing age in COP but not in controls. LLMs can use easily collected language samples to detect COP and identify changes in language that could be targeted to improve communication.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.09.17.26363314","type":"posted-content","created":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T22:40:10Z","timestamp":1789944010000},"source":"Crossref","is-referenced-by-count":0,"title":["Large language model linguistic perplexity in childhood onset psychosis: unique features and developmental trends"],"prefix":"10.64898","author":[{"given":"Anthony J.","family":"Deo","sequence":"first","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"},{"name":"Psychiatric Evaluation of Adolescent and Child Experiences (PEACE) Program, Rutgers University Behavioral Health Care, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cynthia","family":"Lando","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew","family":"Carolan","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuli","family":"Fradkin","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ameerah","family":"Ali","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thanharat","family":"Silamongkol","sequence":"additional","affiliation":[{"name":"Graduate School of Applied and Professional Psychology, Rutgers University, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emi","family":"Carpenter","sequence":"additional","affiliation":[{"name":"Graduate School of Applied and Professional Psychology, Rutgers University, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chloe","family":"Rosenkranz","sequence":"additional","affiliation":[{"name":"Graduate School of Applied and Professional Psychology, Rutgers University, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Escoto","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"},{"name":"Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caraline","family":"McDonnell","sequence":"additional","affiliation":[{"name":"Graduate School of Applied and Professional Psychology, Rutgers University, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6999-1920","authenticated-orcid":false,"given":"Rui","family":"He","sequence":"additional","affiliation":[{"name":"Department of Translation C Language Sciences, Universitat Pompeu Fabra, Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wolfram","family":"Hinzen","sequence":"additional","affiliation":[{"name":"Department of Translation C Language Sciences, Universitat Pompeu Fabra, Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"William W.","family":"Graves","sequence":"additional","affiliation":[{"name":"Department of Psychology, Rutgers University, Newark, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johanne","family":"Solis","sequence":"additional","affiliation":[{"name":"The Rutgers-Princeton Center for Computational Cognitive Neuropsychiatry, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Walter","family":"Barr","sequence":"additional","affiliation":[{"name":"Psychiatric Evaluation of Adolescent and Child Experiences (PEACE) Program, Rutgers University Behavioral Health Care, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emma","family":"Deaso","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Behavioral Sciences, Boston Children\u2019s Hospital, Harvard Medical School, Boston, MA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Glahn","sequence":"additional","affiliation":[{"name":"Department of Psychiatry and Behavioral Sciences, Boston Children\u2019s Hospital, Harvard Medical School, Boston, MA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michele","family":"Pato","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Zald","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlos","family":"Pato","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026092309301692000_2026.09.17.26363314v1.1","doi-asserted-by":"publisher","DOI":"10.1089\/cap.2015.0097"},{"key":"2026092309301692000_2026.09.17.26363314v1.2","doi-asserted-by":"publisher","DOI":"10.1097\/00004583-199510000-00011"},{"key":"2026092309301692000_2026.09.17.26363314v1.3","doi-asserted-by":"publisher","DOI":"10.1111\/eip.12412"},{"key":"2026092309301692000_2026.09.17.26363314v1.4","doi-asserted-by":"publisher","DOI":"10.1192\/bjp.bp.108.060723"},{"key":"2026092309301692000_2026.09.17.26363314v1.5","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.schbul.a033495"},{"key":"2026092309301692000_2026.09.17.26363314v1.6","doi-asserted-by":"publisher","DOI":"10.1093\/schbul\/23.1.105"},{"key":"2026092309301692000_2026.09.17.26363314v1.7","doi-asserted-by":"publisher","DOI":"10.1176\/appi.ajp.157.5.794"},{"key":"2026092309301692000_2026.09.17.26363314v1.8","doi-asserted-by":"publisher","DOI":"10.1177\/0706743721990822"},{"key":"2026092309301692000_2026.09.17.26363314v1.9","doi-asserted-by":"publisher","DOI":"10.1038\/s41537-018-0067-3"},{"key":"2026092309301692000_2026.09.17.26363314v1.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.cortex.2013.02.006"},{"key":"2026092309301692000_2026.09.17.26363314v1.11","doi-asserted-by":"publisher","DOI":"10.1016\/j.jneuroling.2009.07.004"},{"key":"2026092309301692000_2026.09.17.26363314v1.12","doi-asserted-by":"publisher","DOI":"10.1038\/npjschz.2015.30"},{"key":"2026092309301692000_2026.09.17.26363314v1.13","doi-asserted-by":"publisher","DOI":"10.1002\/wps.20491"},{"key":"2026092309301692000_2026.09.17.26363314v1.14","doi-asserted-by":"publisher","DOI":"10.1016\/j.schres.2007.03.001"},{"key":"2026092309301692000_2026.09.17.26363314v1.15","doi-asserted-by":"publisher","DOI":"10.1038\/s41398-021-01722-y"},{"key":"2026092309301692000_2026.09.17.26363314v1.16","doi-asserted-by":"crossref","unstructured":"Iter D , Yoon J , Jurafsky D , editors. Automatic detection of incoherent speech for diagnosing schizophrenia. Proceedings of the Fifth Workshop on Computational Linguistics and Clinical Psychology: From Keyboard to Clinic; 2018.","DOI":"10.18653\/v1\/W18-0615"},{"key":"2026092309301692000_2026.09.17.26363314v1.17","doi-asserted-by":"publisher","DOI":"10.1016\/j.psychres.2024.115752"},{"key":"2026092309301692000_2026.09.17.26363314v1.18","doi-asserted-by":"publisher","DOI":"10.1038\/s41537-022-00246-8"},{"key":"2026092309301692000_2026.09.17.26363314v1.19","doi-asserted-by":"publisher","DOI":"10.1093\/schizbullopen\/sgac054"},{"key":"2026092309301692000_2026.09.17.26363314v1.20","doi-asserted-by":"publisher","DOI":"10.1016\/j.schres.2022.07.002"},{"key":"2026092309301692000_2026.09.17.26363314v1.21","doi-asserted-by":"publisher","DOI":"10.1016\/j.psychres.2021.114130"},{"key":"2026092309301692000_2026.09.17.26363314v1.22","doi-asserted-by":"publisher","DOI":"10.1016\/j.jcomdis.2022.106182"},{"key":"2026092309301692000_2026.09.17.26363314v1.23","doi-asserted-by":"publisher","DOI":"10.1093\/schbul\/sbac194"},{"key":"2026092309301692000_2026.09.17.26363314v1.24","doi-asserted-by":"publisher","DOI":"10.1016\/j.schres.2022.06.011"},{"key":"2026092309301692000_2026.09.17.26363314v1.25","doi-asserted-by":"publisher","DOI":"10.1038\/s43856-025-00944-1"},{"key":"2026092309301692000_2026.09.17.26363314v1.26","doi-asserted-by":"crossref","unstructured":"Jawahar G , Sagot B , Seddah D , editors. What does BERT learn about the structure of language? ACL 2019-57th Annual Meeting of the Association for Computational Linguistics; 2019.","DOI":"10.18653\/v1\/P19-1356"},{"key":"2026092309301692000_2026.09.17.26363314v1.27","unstructured":"Limisiewicz T , Mare\u010dek D . Syntax Representation in Word Embeddings and Neural Networks--A Survey. arXiv preprint arXiv:201001063. 2020."},{"key":"2026092309301692000_2026.09.17.26363314v1.28","doi-asserted-by":"publisher","DOI":"10.1503\/jpn.240031"},{"key":"2026092309301692000_2026.09.17.26363314v1.29","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbi.2025.104899"},{"key":"2026092309301692000_2026.09.17.26363314v1.30","doi-asserted-by":"publisher","DOI":"10.1097\/00004583-200006000-00016"},{"key":"2026092309301692000_2026.09.17.26363314v1.31","doi-asserted-by":"crossref","unstructured":"Davis EA . Mean sentence length compared with long and short sentences as a reliable measure of language development. Child Development. 1937:69\u201379.","DOI":"10.2307\/1125824"},{"key":"2026092309301692000_2026.09.17.26363314v1.32","doi-asserted-by":"publisher","DOI":"10.1192\/bjp.156.2.204"},{"key":"2026092309301692000_2026.09.17.26363314v1.33","doi-asserted-by":"publisher","DOI":"10.1016\/0165-1781(83)90048-3"},{"key":"2026092309301692000_2026.09.17.26363314v1.34","unstructured":"Nayeem MT , Rafiei D. KidLM: Advancing Language Models for Children\u2013Early Insights and Future Directions."},{"key":"2026092309301692000_2026.09.17.26363314v1.35","doi-asserted-by":"publisher","DOI":"10.2202\/1547-7355.1792"},{"key":"2026092309301692000_2026.09.17.26363314v1.36","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaac.2019.05.009"},{"key":"2026092309301692000_2026.09.17.26363314v1.37","doi-asserted-by":"publisher","DOI":"10.1097\/00004583-199707000-00021"},{"key":"2026092309301692000_2026.09.17.26363314v1.38","doi-asserted-by":"publisher","DOI":"10.1176\/appi.ajp.159.5.863"},{"key":"2026092309301692000_2026.09.17.26363314v1.39","doi-asserted-by":"publisher","DOI":"10.1177\/0706743719856845"},{"key":"2026092309301692000_2026.09.17.26363314v1.40","doi-asserted-by":"publisher","DOI":"10.1097\/00004583-198905000-00018"},{"key":"2026092309301692000_2026.09.17.26363314v1.41","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaac.2011.03.021"},{"key":"2026092309301692000_2026.09.17.26363314v1.42","doi-asserted-by":"publisher","DOI":"10.1080\/17470218.2014.988735"},{"key":"2026092309301692000_2026.09.17.26363314v1.43","doi-asserted-by":"publisher","DOI":"10.1038\/s41537-021-00154-3"},{"key":"2026092309301692000_2026.09.17.26363314v1.44","unstructured":"Kyle K . Measuring syntactic development in L2 writing: Fine-grained indices of syntactic complexity and usage-based indices of syntactic sophistication [Doctoral dissertation]. Atlanta, GA: Georgia State University; 2016."},{"key":"2026092309301692000_2026.09.17.26363314v1.45","doi-asserted-by":"crossref","unstructured":"Miaschi A , Brunato D , Dell\u2019Orletta F , Venturi G , editors. What makes my model perplexed? a linguistic investigation on neural language models perplexity. Proceedings of Deep Learning Inside Out (DeeLIO): The 2nd Workshop on Knowledge Extraction and Integration for Deep Learning Architectures; 2021.","DOI":"10.18653\/v1\/2021.deelio-1.5"},{"issue":"9","key":"2026092309301692000_2026.09.17.26363314v1.46","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1111\/lnc3.12196","article-title":"Information-theoretical complexity metrics","volume":"10","year":"2016","journal-title":"Language and Linguistics Compass"},{"key":"2026092309301692000_2026.09.17.26363314v1.47","unstructured":"Touvron H , Lavril T , Izacard G , Martinet X , Lachaux M-A , Lacroix T , Rozi\u00e8re B , Goyal N , Hambro E , Azhar F , Rodriguez A , Joulin A , Grave E , Lample G. LLaMA: Open and Efficient Foundation Language Models. 2023."},{"key":"2026092309301692000_2026.09.17.26363314v1.48","first-page":"4171","article-title":"BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding","volume":"1","year":"2019","journal-title":"2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies (Naacl Hlt 2019)"},{"key":"2026092309301692000_2026.09.17.26363314v1.49","doi-asserted-by":"publisher","DOI":"10.1097\/CHI.0b013e31816bffb7"},{"key":"2026092309301692000_2026.09.17.26363314v1.50","doi-asserted-by":"crossref","unstructured":"Salazar J , Liang D , Nguyen TQ , Kirchhoff K , editors. Masked Language Model Scoring2020 July; Online: Association for Computational Linguistics.","DOI":"10.18653\/v1\/2020.acl-main.240"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.09.17.26363314","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T16:30:30Z","timestamp":1790181030000},"score":1,"resource":{"primary":{"URL":"http:\/\/medrxiv.org\/lookup\/doi\/10.64898\/2026.09.17.26363314"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,20]]},"references-count":50,"URL":"https:\/\/doi.org\/10.64898\/2026.09.17.26363314","relation":{},"subject":[],"published":{"date-parts":[[2026,9,20]]},"subtype":"preprint"}}