Picture naming: Stereoelectroencephalography and connectivity insights

This study investigates the neural substrates of picture naming (PN) using stereoelectroencephalographic (SEEG) stimulations and evaluates the contribution of white matter (WM) fascicles related to the basal temporal language area (BTLA) to the broader functional PN network.

In patients undergoing SEEG for drug-resistant epilepsy, stimulation sites were classified as either eloquent (inducing anomia) or noneloquent (NE). Spatial distribution was assessed along the ventral temporal cortex (VTC). Structural connectivity was analyzed using voxelwise disconnectome mapping, connectivity profiles were compared between eloquent and NE sites, and Uniform Manifold Approximation and Projection (UMAP) was applied to characterize the organization of disconnectomes associated with eloquent sites.

Eloquent sites were predominantly located along the VTC, following an anteroposterior gradient, with the highest probability in the posterior fusiform gyrus. These sites showed the strongest overlap with the inferior longitudinal fasciculus (ILF), and eloquent-site disconnectomes primarily involved the ILF and inferior fronto-occipital fasciculus. Voxelwise comparisons revealed distinct network profiles between eloquent and NE sites, characterized by higher inferred connectivity in anomia-derived disconnectomes. UMAP demonstrated an anteroposterior organization of disconnection patterns, reflecting structural heterogeneity across the BTLA.

PN appears to depend on a ventral temporo-occipital network organized along an anteroposterior gradient within the VTC, where naming performance may rely more on the integrity of ventral WM pathways than on cortical location alone. The BTLA emerges as a structurally heterogeneous region shaped by the progressive overlap of WM pathways from anterior to posterior temporal regions. These results support integrating SEEG mapping and individualized ventral WM assessment into surgical planning.