Dissociated face- and word-selective intracerebral responses in the human ventral occipito-temporal cortex

Simen Hagen (1, 2) , Aliette Lochy (3) , Corentin Jacques (4) , Louis Maillard (1, 5) , Sophie Colnat-Coulbois (1, 6) , Jacques Jonas (1, 5) , Bruno Rossion (1, 4, 5)

1 CRAN - Centre de Recherche en Automatique de Nancy
2 Donders Institute for Brain, Cognition and Behaviour
3 University of Luxembourg [Luxembourg]
4 UCL - Université Catholique de Louvain = Catholic University of Louvain
5 Service de neurologie [CHRU Nancy]
6 Service de Neurochirurgie [CHRU Nancy]

The extent to which faces and written words share neural circuitry in the human brain is actively debated. Here, we compare face-selective and word-selective responses in a large group of patients (N = 37) implanted with intracerebral electrodes in the ventral occipito-temporal cortex (VOTC). Both face-selective (i.e., significantly different responses to faces vs. non-face visual objects) and word-selective (i.e., significantly different responses to words vs. pseudofonts) neural activity is isolated with frequency-tagging. Critically, this sensitive approach allows to objectively quantify category-selective neural responses and disentangle them from general visual responses. About 70% of significant electrode contacts show either face-selectivity or word-selectivity only, with the expected right and left hemispheric dominance, respectively. Spatial dissociations are also found within core regions of face and word processing, with a medio-lateral dissociation in the fusiform gyrus (FG) and surrounding sulci, respectively. In the 30% of overlapping face-and word-selective contacts across the VOTC or in the FG and surrounding sulci, between-category-selective amplitudes (faces vs. words) show no-to-weak correlations, despite strong correlations in both the within-category-selective amplitudes (face-face, word-word) and the general visual responses to words and faces. Overall, these observations support the view that category-selective circuitry for faces and written words is largely dissociated in the human adult VOTC.

Mots clés: Face categorization; Word categorization; Frequency-tagging; SEEG; Fusiform gyrus; Anterior temporal lobe

Domaines: Sciences du Vivant [q-bio]

Simen Hagen, Aliette Lochy, Corentin Jacques, Louis Maillard, Sophie Colnat-Coulbois, et al.. Dissociated face- and word-selective intracerebral responses in the human ventral occipito-temporal cortex. Brain Structure and Function, 2021, 226 (9), pp.3031-3049. ⟨10.1007/s00429-021-02350-4⟩. ⟨hal-03437752⟩