The left inferior frontal gyrus is crucial for reading the mind in the eyes: brain lesion evidence.

Deficit in the ability to understand and predict the mental states of others is one of the central features of traumatic brain injury (TBI), leading to problems in social-daily life such as social withdrawal and the inability to maintain work or family relationships. Although several functional neuroimaging studies have identified a widely distributed brain network involved in the Reading the Mind in the Eyes Test (RMET), the necessary brain regions engaged in this capacity are still heavily debated. In this study, we combined the RMET with a whole-brain voxel-based lesion symptom mapping (VLSM) approach to identify brain regions necessary for adequate RMET performance in a large sample of patients with penetrating TBI (pTBI). Our results revealed that pTBI patients performed worse on the RMET compared to non-head injured controls, and impaired RMET performance was associated with lesions in the left inferior frontal gyrus (IFG). Our findings suggest that the left IFG is a key region in reading the mind in the eyes, probably involved in a more general impairment of a semantic working memory system that facilitates reasoning about what others are feeling and thinking as expressed by the eyes.