P 15 Voice-identity processing deficits are induced by lesions in the temporal and inferior parietal lobe

Human voice recognition is an essential skill for social interactions. The mechanisms that the human brain uses for voice recognition are to-date unknown. According to studies in patients with brain lesions, voice recognition critically involves the bilateral temporal lobe and the right inferior parietal lobe. In contrast, functional magnetic resonance imaging (fMRI) studies suggest that primarily the right temporal lobe contributes to voice recognition. In order to systematically investigate brain regions required for voice recognition, we conducted a voxel-based lesion symptom mapping (VLSM) study. The study included a comprehensive behavioral test battery, neuropsychological assessment and high-resolution structural brain images. We tested 58 patients having unilateral focal brain lesions on unfamiliar and familiar voice recognition as well as face recognition skills. VLSM analysis revealed three key findings. (i) A strong association between right temporal and right inferior parietal lobe lesions and voice-recognition deficits. (ii) Only the association of the right temporal lobe with voice-recognition deficits remained significant when we controlled for face-recognition performance. (iii) Unfamiliar voice-recognition deficits were associated with lesions in the right temporal lobe as well as in the right inferior parietal lobe. The ability to recognize familiar voices was associated with left posterior temporal lobe lesions. Our results help to explain the discrepancies between previous lesion and fMRI findings. They show that both the right temporal lobe and the parietal lobe play critical roles for voice-recognition abilities. The right temporal lobe might be key for the representation of the voice and speaker identity, while the parietal lobe might be involved in a more multimodal representation of person identities.