title: Direct evidence for the contributive role of the right inferior fronto-occipital fasciculus in non-verbal semantic cognition.
abstract: The neural foundations underlying semantic processing have been extensively investigated, highlighting a pivotal role of the ventral stream. However, although studies concerning the involvement of the left ventral route in verbal semantics are proficient, the potential implication of the right ventral pathway in non-verbal semantics has been to date unexplored. To gain insights on this matter, we used an intraoperative direct electrostimulation to map the structures mediating the non-verbal semantic system in the right hemisphere. Thirteen patients presenting with a right low-grade glioma located within or close to the ventral stream were included. During the 'awake' procedure, patients performed both a visual non-verbal semantic task and a verbal (control) task. At the cortical level, in the right hemisphere, we found non-verbal semantic-related sites (n = 7 in 6 patients) in structures commonly associated with verbal semantic processes in the left hemisphere, including the superior temporal gyrus, the pars triangularis, and the dorsolateral prefrontal cortex. At the subcortical level, we found non-verbal semantic-related sites in all but one patient (n = 15 sites in 12 patients). Importantly, all these responsive stimulation points were located on the spatial course of the right inferior fronto-occipital fasciculus (IFOF). These findings provide direct support for a critical role of the right IFOF in non-verbal semantic processing. Based upon these original data, and in connection with previous findings showing the involvement of the left IFOF in non-verbal semantic processing, we hypothesize the existence of a bilateral network underpinning the non-verbal semantic system, with a homotopic connectional architecture.
authors: Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, 34295, Montpellier, France. guillaume.herbet@gmail.com.|National Institute for Health and Medical Research (INSERM), U1051, Team "Plasticity of the Central Nervous System, Human Stem Cells and Glial Tumors", Institute for Neurosciences of Montpellier, Montpellier University Medical Center, 80 Av Augustin Fliche, 34091, Montpellier, France. guillaume.herbet@gmail.com.|University of Montpellier, 163 rue Auguste Broussonnet, 34090, Montpellier, France. guillaume.herbet@gmail.com.
authors: Guillaume
authors: G
authors: Herbet
authors: Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, 34295, Montpellier, France.|National Institute for Health and Medical Research (INSERM), U1051, Team "Plasticity of the Central Nervous System, Human Stem Cells and Glial Tumors", Institute for Neurosciences of Montpellier, Montpellier University Medical Center, 80 Av Augustin Fliche, 34091, Montpellier, France.|University of Montpellier, 163 rue Auguste Broussonnet, 34090, Montpellier, France.
authors: Sylvie
authors: S
authors: Moritz-Gasser
authors: Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, 34295, Montpellier, France.|National Institute for Health and Medical Research (INSERM), U1051, Team "Plasticity of the Central Nervous System, Human Stem Cells and Glial Tumors", Institute for Neurosciences of Montpellier, Montpellier University Medical Center, 80 Av Augustin Fliche, 34091, Montpellier, France.|University of Montpellier, 163 rue Auguste Broussonnet, 34090, Montpellier, France.
authors: Hugues
authors: H
authors: Duffau
mesh_terms: D000328:Adult; D000368:Aged; D001369:Axons / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology; D012660:Semantics; D014796:Visual Perception / Q000502:physiology; D066127:White Matter / Q000502:physiology*; D055815:Young Adult
keywords: Electrostimulation mapping; Inferior fronto-occipital fasciculus; Naming; Non-verbal semantic processing; Right hemisphere; Ventral stream