Hope 희진 Kean

The Neural Architecture of Reasoning

I study how the brain supports abstract thought. Does reasoning depend on language? Why does formal inference have its own architecture? How do cognitive systems emerge in profoundly atypical brains?

01 / Logic

A brain network specialized for abstract formal reasoning

Using a deep-data, precision fMRI approach, I identified a set of frontal regions selectively engaged by structure-sensitive inference, whether verbal, symbolic, visuo-spatial, or mathematical. This logic system is dissociable from the Multiple Demand network, suggesting a dedicated substrate for formal symbolic thought that is not reducible to executive function.

Media: Artistic collaboration

02 / Language

Diverse forms of reasoning do not rely on linguistic representations

Across fMRI studies matched for difficulty and structure, the regions engaged during reasoning are functionally and spatially dissociable from the left perisylvian language network. Individuals with profound aphasia can retain typical-like deductive and inductive reasoning, showing that language is not the representational format of thought.

Kean et al. 2026, PNAS
Media: WSJ | MIT News

03 / Lesions

Building a mind in an atypical brain

The Interesting Brains Project studies nearly 50 individuals with profound neuroanatomical anomalies, including large arachnoid cysts, early-life strokes, and agenesis of the corpus callosum. High-level systems, including the logic network, emerge intact and typically organized despite radically altered cortical architecture.

InterestingBrains.com | Media: NYT article

Papers

View full profile on Google Scholar →

Evidence from formal logical reasoning reveals that the language of thought is not natural language. Kean, H., Fung, A., Jaggers, P., Chen, J., Rule, J., Benn, Y., Tenenbaum, J., Piantadosi, S., Varley, R., & Fedorenko, E. (2026). PNAS.
A human brain network specialized for abstract formal reasoning. Kean, H., Fung, A., Chen, J., Ohams, C., Rule, J., Tenenbaum, J., Piantadosi, S., & Fedorenko, E. Under review.
Functional specificity is a core principle of human brain organization, as revealed by highly anatomically atypical brains. Kean, H., Wolna, A., Swords, S., Jhingan, N., Shewmon, A., Richardson, M., & Fedorenko, E. Forthcoming; see version in thesis.
The neural architecture of human reasoning: Higher-order cognitive specialization for formal thought and in atypical brains. Kean, H. (2025). Doctoral dissertation, MIT.
Intuitive physical reasoning is not mediated by linguistic nor exclusively domain-general abstract representations. Kean, H., Fung, A., Pramod, RT., Chomik-Morales, J., Kanwisher, N., & Fedorenko, E. (2025). Neuropsychologia.
The cost of thinking is similar between large reasoning models and humans. deVarda, A., D’Elia, F., Kean, H., Lampinen, A., & Fedorenko, E. (2026). PNAS.
The language network responds robustly to sentences across diverse tasks. Gao, R., Cheung, C., Siegelman, M., Pongos, A., Kean, H., Tanner, A., Fedorenko, E., & Ivanova, A. (2026). Imaging Neuroscience.
Semantic reasoning takes place largely outside the language network. Ivanova, A., Kauf, C., Gao, R., She, J., Kean, H., Goldhaber, T., Nieto-Castañón, A., Varley, R., Kanwisher, N., & Fedorenko, E. (2026). Under review.
Distributed sensitivity to syntax and semantics throughout the language network. Shain*, C., Kean*, H., Casto, C., Lipkin, B., Affourtit, J., Siegelman, M., Mollica, F., & Fedorenko, E. (2024). Journal of Cognitive Neuroscience.
Preserved functional organization of human auditory cortex in individuals missing one temporal lobe from birth. Regev, T., Lipkin, B., Boebinger, D., Paunov, A., Kean, H., Norman-Haignere, S.V., & Fedorenko, E. (2024). iScience.
Intact reading ability despite lacking a canonical visual word form area in an individual born without the left superior temporal lobe. Li, J., Kean, H., Fedorenko, E., & Saygin, Z. (2022). Cognitive Neuropsychology.
Frontal language areas do not emerge in the absence of temporal language areas: A case study of an individual born without a left temporal lobe. Tuckute, G., Paunov, A., Kean, H., Small, H., Mineroff, Z., Blank, I.A., & Fedorenko, E. (2022). Neuropsychologia.
Precision fMRI reveals that the language-selective network supports both phrase-structure building and lexical access during language production. Hu, J., Small, H., Kean, H., Takahashi, A., Zekelman, L., Kleinman, D., Ryan, E., Nieto-Castañón, A., Ferreira, V., & Fedorenko, E. (2022). Cerebral Cortex.
The human language system does not support music processing. Chen, X., Affourtit, J., Ryskin, R., Regev, T., Norman-Haignere, S., Jouravlev, O., Malik-Moraleda, S., Kean, H., Varley, R., & Fedorenko, E. (2022). Cerebral Cortex.
LanA (Language Atlas): A probabilistic atlas for the language network based on fMRI data from >800 individuals. Lipkin, B., Tuckute, G., Affourtit, J., Small, H., Mineroff, Z., Kean, H., Jouravlev, O., Rakocevic, L., Pritchett, B., Siegelman, M., Hoeflin, C., Pongos, A., Blank, I., Kline, M., Ivanova, A., Shannon, S., Sathe, A., Hoffman, M., Nieto-Castañón, A., & Fedorenko, E. (2022). Nature Scientific Data.
Comprehension of computer code relies primarily on domain-general executive brain regions. Ivanova, A., Srikant, S., Sueoka, Y., Kean, H., Dhamala, R., O’Reilly, U., Bers, M., & Fedorenko, E. (2020). eLife.
Composition is the core driver of the language-selective network. Mollica, F., Siegelman, M., Diachek, E., Piantadosi, S., Futrell, R., Mineroff, Z., Kean, H., Qian, P., & Fedorenko, E. (2020). Neurobiology of Language.
Implicit model of other people’s visual attention as an invisible, force-carrying beam projecting from the eyes. Guterstam*, A., Kean*, H., Webb, T., Kean, F., & Graziano, G. (2018). PNAS.
Effects of awareness on the control of attention. Webb, T., Kean, H., & Graziano, M. (2016). Journal of Cognitive Neuroscience.

In prep

Logic, simple arithmetic, and language co-lateralize in the human brain. Kean, H., Diachek, E., Blank, I., & Fedorenko, E. In prep.
Distributed neural mechanisms of inductive inference. Kean, H., Fung, A., Chen, J., Rule, J., Tenenbaum, J., Piantadosi, S., & Fedorenko, E. In prep.
Why language representations are an impoverished format for thought. Kean*, H., deVarda*, A., Piantadosi, S., & Fedorenko, E. In prep.