1 Department of Neurosurgery, Gui de Chauliac hospital, F-34295 Montpellier, France2 Institute for Neuroscience of Montpellier, INSERM 1051, Hôpital Saint Eloi, F-34091 Montpellier, France3 University of Montpellier 1, F-34967 Montpellier, France
4 Functional Neuroscience and Pathologies Laboratory, EA-4559, Lille Nord de France University, F-59120 Loos, France5 Department of Psychology, Lille Nord de France University (Lille3), F-59653 Villeneuve d’Ascq, France
6 Cognition, Action and Sensorimotor Plasticity Lab, INSERM U-1093, UFR STAPS, F-27877 Dijon, France7 University of Montpellier 2, LIRMM, DEMAR team, CNRS, INRIA, F-34095 Montpellier, France8 University Institute of France, F-75005 Paris, France
1 Department of Neurosurgery, Gui de Chauliac hospital, F-34295 Montpellier, France9 Department of Neurology, Gui de Chauliac hospital, F-34295 Montpellier, France
Nicolas Menjot de Champfleur
10 Department of Neuroradiology, Gui de Chauliac hospital, F-34295 Montpellier, France
1 Department of Neurosurgery, Gui de Chauliac hospital, F-34295 Montpellier, France2 Institute for Neuroscience of Montpellier, INSERM 1051, Hôpital Saint Eloi, F-34091 Montpellier, France
In the field of cognitive neuroscience, it is increasingly accepted that mentalizing is subserved by a complex frontotemporoparietal cortical network. Some researchers consider that this network can be divided into two distinct but interacting subsystems (the mirror system and the mentalizing system per se), which respectively process low-level, perceptive-based aspects and high-level, inference-based aspects of this sociocognitive function. However, evidence for this type of functional dissociation in a given neuropsychological population is currently lacking and the structural connectivities of the two mentalizing subnetworks have not been established. Here, we studied mentalizing in a large sample of patients (n = 93; 46 females; age range: 18–65 years) who had been resected for diffuse low-grade glioma—a rare tumour that migrates preferentially along associative white matter pathways. This neurological disorder constitutes an ideal pathophysiological model in which to study the functional anatomy of associative pathways. We mapped the location of each patient’s resection cavity and residual lesion infiltration onto the Montreal Neurological Institute template brain and then performed multilevel lesion analyses (including conventional voxel-based lesion-symptom mapping and subtraction lesion analyses). Importantly, we estimated each associative pathway’s degree of disconnection (i.e. the degree of lesion infiltration) and built specific hypotheses concerning the connective anatomy of the mentalizing subnetworks. As expected, we found that impairments in mentalizing were mainly related to the disruption of right frontoparietal connectivity. More specifically, low-level and high-level mentalizing accuracy were correlated with the degree of disconnection in the arcuate fasciculus and the cingulum, respectively. To the best of our knowledge, our findings constitute the first experimental data on the structural connectivity of the mentalizing network and suggest the existence of a dual-stream hodological system. Our results may lead to a better understanding of disorders that affect social cognition, especially in neuropathological conditions characterized by atypical/aberrant structural connectivity, such as autism spectrum disorders.