Picture naming: Stereoelectroencephalography and connectivity insights

Area of Science:

• Neuroscience
• Neurolinguistics
• Neurosurgery

Background:

• Picture naming (PN) is a complex cognitive task.
• Understanding the neural basis of PN is crucial for clinical applications, especially in neurosurgery.
• The basal temporal language area (BTLA) is implicated in PN, but its precise functional network and white matter (WM) contributions remain unclear.

Purpose of the Study:

• To investigate the neural substrates of PN using stereoelectroencephalographic (SEEG) stimulations.
• To evaluate the contribution of WM fascicles within the BTLA to the functional PN network.
• To explore the relationship between cortical stimulation sites and WM connectivity.

Main Methods:

• Stereoelectroencephalographic (SEEG) stimulations were performed in patients with drug-resistant epilepsy.
• Stimulation sites were classified as eloquent (inducing anomia) or noneloquent (NE).
• Voxelwise disconnectome mapping and Uniform Manifold Approximation and Projection (UMAP) were used to analyze structural connectivity and network organization.

Main Results:

• Eloquent sites for PN were located along the ventral temporal cortex (VTC), with an anteroposterior gradient, particularly in the posterior fusiform gyrus.
• These sites strongly overlapped with the inferior longitudinal fasciculus (ILF) and inferior fronto-occipital fasciculus.
• Disconnectome analysis revealed distinct network profiles for eloquent sites, indicating higher inferred connectivity, and UMAP showed an anteroposterior organization of disconnection patterns.

Conclusions:

• PN depends on a ventral temporo-occipital network organized along an anteroposterior gradient in the VTC.
• The integrity of ventral WM pathways is critical for naming performance, potentially more so than cortical location alone.
• The BTLA is structurally heterogeneous, and integrating SEEG mapping with WM assessment is recommended for surgical planning.