Hi! I’m Kohei Kajikawa, a first-year Ph.D. student in Computational Linguistics at Georgetown, advised by Prof. Ethan G. Wilcox.
My research lies at the intersection of psycholinguistics and computational linguistics. I study how humans comprehend sentences incrementally, that is, how hierarchical, multi-layered linguistic information is processed under cognitive resource constraints. I am also interested in why language structures are the way they are. I investigate the extent to which processing efficiency can, and cannot, account for cross-linguistic syntactic patterns.
Previously, I was at National Institute for Japanese Language and Linguistics (NINJAL), working with Prof. Yusuke Kubota and Prof. Shinnosuke Isono. Before that, I earned my M.A. and B.A. in Linguistics from The University of Tokyo.
日本での活動についてはこちら (Activities in Japan)
- 📄: CV
- ✉️:
kk1571 [at] georgetown.edu - 🔗: [Google Scholar] [Twitter] [GitHub] [ResearchGate]
News
- 02.2026: Our new preprint is out! We propose an information-theoretic storage cost!
- 01.2026: Check out our new preprint on the nature of syntactic Node Count!
- 08.2025: Started PhD at Georgetown Linguistics.
- 12.2024: Best Paper Award at CoNLL2024.
→ Older news
Publications
Preprints
- Kohei Kajikawa, Shinnosuke Isono, and Ethan Gotlieb Wilcox. Information-Theoretic Storage Cost in Sentence Comprehension. [arXiv]
- Kohei Kajikawa and Shinnosuke Isono. The Dual Nature of Syntactic Node Count: Facilitating and Inhibiting Sentence Comprehension. [PsyArXiv]
- Shinnosuke Isono, Kohei Kajikawa, Yohei Oseki, and Masayuki Asahara. Modeling memory effects in a head-final language with category locality. [PsyArXiv]
- Kai Nakaishi, Ryo Yoshida, Kohei Kajikawa, Koji Hukushima, and Yohei Oseki. Rethinking the Relationship between the Power Law and Hierarchical Structures. To appear in TACL [arXiv]
Conference Proceedings
- Ryo Yoshida, Shinnosuke Isono, Kohei Kajikawa, Taiga Someya, Yushi Sugimoto, and Yohei Oseki. 2025. If Attention Serves as a Cognitive Model of Human Memory Retrieval, What is the Plausible Memory Representation?. ACL. [pdf]
- Kohei Kajikawa, Yusuke Kubota, and Yohei Oseki. 2024. Is Structure Dependence Shaped for Efficient Communication?: A Case Study on Coordination. CoNLL. 🏆Best Paper Award [pdf] [slides] [code]
- Kohei Kajikawa, Ryo Yoshida, and Yohei Oseki. 2024. Dissociating Syntactic Operations via Composition Count. CogSci. [pdf] [slides] [code]
- Shinnosuke Isono, Takuya Hasegawa, Kohei Kajikawa, Koichi Kono, Shiho Nakamura, and Yohei Oseki. 2023. Formalizing Argument Structures with Combinatory Categorial Grammar. Logic and Engineering of Natural Language Semantics (LENLS). [pdf] [slides]
Conference Presentations/Posters
- Kohei Kajikawa and Ethan Gotlieb Wilcox. 2026. Spillover as Rational Processing Delay in Sentence Comprehension. Human Sentence Processing (HSP2026). [abstract]
- Shinnosuke Isono and Kohei Kajikawa. 2025. Grammar as logic, processing as deduction, actions as theorems, states as propositions. Computational Psycholinguistics Meeting (CPL). 📣Spotlight poster presentation [abstract] [poster]
- Kohei Kajikawa and Shinnosuke Isono. 2025. Syntactic Node Count as Index of Predictability. Computational Psycholinguistics Meeting (CPL). [abstract] [poster]
- Kohei Kajikawa*, Shinnosuke Isono*, Yushi Sugimoto*, Masayuki Asahara, and Yohei Oseki. 2025. Exploring spatial and temporal dynamics of language comprehension in the brain with CCG. CogSci. (*=equal contribution) [url] [poster]
- Kohei Kajikawa. 2023. Analyzing Japanese Cleft Construction in Combinatory Categorial Grammar. Logic and Engineering of Natural Language Semantics (LENLS). [abstract] [slides]
Awards and Honors
- 12.2024: Best Paper Award. CoNLL2024
- 06.2025: Director’s Award. NINJAL
- 06.2025: Young Researcher Encouragement Award. NINJAL
- 03.2025: Young Researcher Encouragement Award. ANLP
- 03.2025: Committee Special Award. ANLP
- 03.2024: Committee Special Award. ANLP
Grants and Fellowships
- 12.2025: Travel Grant for Computational Psycholinguistics Meeting 2025 supported by MultiplEYE COST Action
- 12.2025: Travel Grant supported by Department of Linguistics, Georgetown University
- 04.2025 - 03.2028: JSPS Research Fellowship (DC1) [kaken]
- JPY 200,000/month + JPY 3,900,000 (research grant over 3 yrs)
- 09.2025: Declined the fellowship upon accepting an offer to pursue doctoral training abroad.
Academic Service
Peer Reviewing
- CoNLL2025 (Outstanding reviewer), LREC2026
Education
- 08.2025 - Present: Ph.D. in Computational Linguistics, Georgetown University
- 04.2025 - 08.2025: Ph.D. in Linguistics, National Institute for Japanese Language and Linguistics (NINJAL)
- 04.2023 - 03.2025: M.A. in Linguistics, The University of Tokyo
- 04.2019 - 03.2023: B.A. in Linguistics (minor in Computer Science), The University of Tokyo