Dissociation Between Physical Reasoning and Tool Use in Individuals With Left Hemisphere Brain Damage

Authors

• Shuchen Liu
• Seda Karakose-Akbiyik
• Alfonso Caramazza
• Filipa Dourado Sotero
• Laurel J. Buxbaum, Thomas Jefferson UniversityFollow
• Aaron L. Wong, Thomas Jefferson UniversityFollow

Document Type

Article

Publication Date

5-12-2026

Comments

This article is the author’s final published version in Cortex, Volume 201, 2026, Pages 148-170.

The published version is available at https://doi.org/10.1016/j.cortex.2026.05.003. Copyright © 2026 The Authors.

Abstract

Tool use and physical reasoning are often assumed to rely on shared cognitive and neural mechanisms. At some level, this correspondence is expected: using an object typically requires understanding its physical properties. However, both capacities are complex and multicomponential, so the relationship between them may vary across levels of representation and task demands. Here, we asked whether third-person physical reasoning about object dynamics can dissociate from tool use (i.e., performing a tool's typical action) in individuals with left-hemisphere stroke. We tested 11 patients, five of whom showed impairments in tool use. Physical reasoning was assessed using a novel collection of tasks probing judgments about mass, velocity, and timing across static and dynamic scenes. Tool use was evaluated using a classic gesture-to-sight task, a pantomime-based measure in which participants are shown pictures of familiar tools and asked to demonstrate how each would be used. We identified an individual-level dissociation: patient I.A.∗ showed impairment in gesturing the use of objects despite preserved physical reasoning, often outperforming neurotypical controls. This pattern was complemented by patient N.P., who showed the reverse profile, with intact tool use gestures but difficulties in some physical reasoning tasks. These findings suggest that the ability to reason about the physical world and tool use can dissociate behaviorally and be independently disrupted by brain damage. This challenges the view that physical reasoning and tool use draw on the same underlying cognitive and neural mechanisms and suggests that at least some of their components are distinct.

∗ Both initials I.A. and N.P. are pseudonyms used to protect participant identities.

Recommended Citation

Liu, Shuchen; Karakose-Akbiyik, Seda; Caramazza, Alfonso; Dourado Sotero, Filipa; Buxbaum, Laurel J.; and Wong, Aaron L., "Dissociation Between Physical Reasoning and Tool Use in Individuals With Left Hemisphere Brain Damage" (2026). Moss-Magee Rehabilitation Papers. Paper 27.
https://jdc.jefferson.edu/mossrehabfp/27

Creative Commons License

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Language

English