Maitre de Conférences – HDR
Neuropsychologie
Nommé Professeur des Universités en 2017 Laboratoire C2S Cognition Santé Société (EA 6291) – Université de Reims
- Faculté : Univ Lille Nord de France – Université de Lille 3
- Membre de l’Axe de Recherche Neuropsychologie : Audition, Cognition, Action
♦ Responsabilités ♦
- Membre élu du Conseil National des Universités (section 16)
- Membre élu du Conseil Scientifique de l’Université Sciences Humaines et Sociales
♦ Publications jusqu’en 2017♦
2017 |
|
| 1. | Herbet, Guillaume; Lafargue, Gilles; Duffau, Hugues Un atlas du potentiel neuroplastique chez les patients cérébrolésés Article de journal Dans: médecine/sciences, 33 (1), p. 84–86, 2017, ISSN: 0767-0974, 1958-5381. @article{herbet_atlas_2017, title = {Un atlas du potentiel neuroplastique chez les patients cérébrolésés}, author = {Guillaume Herbet and Gilles Lafargue and Hugues Duffau}, url = {http://www.medecinesciences.org/10.1051/medsci/20173301014}, doi = {10.1051/medsci/20173301014}, issn = {0767-0974, 1958-5381}, year = {2017}, date = {2017-01-01}, urldate = {2017-03-02}, journal = {médecine/sciences}, volume = {33}, number = {1}, pages = {84--86}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2016 |
|
| 2. | Herbet, Guillaume; Lafargue, Gilles; Duffau, Hugues The dorsal cingulate cortex as a critical gateway in the network supporting conscious awareness Article de journal Dans: Brain, 139 (4), p. e23–e23, 2016, ISSN: 0006-8950, 1460-2156. @article{herbet_dorsal_2016, title = {The dorsal cingulate cortex as a critical gateway in the network supporting conscious awareness}, author = {Guillaume Herbet and Gilles Lafargue and Hugues Duffau}, url = {http://brain.oxfordjournals.org/content/139/4/e23}, doi = {10.1093/brain/awv381}, issn = {0006-8950, 1460-2156}, year = {2016}, date = {2016-04-01}, urldate = {2016-09-07}, journal = {Brain}, volume = {139}, number = {4}, pages = {e23--e23}, abstract = {Sir, We have read with great interest the recent article by Balestrini et al. (2015) reporting a detailed cortical mapping of the parietal cortex. The work is remarkable in that it is based on the electrostimulation data from an impressive cohort of 172 patients with refractory focal epilepsy (419 cortical sites with a clinical response were unmasked), thus permitting authoritative conclusions about the functions of the different regions of the parietal cortex. In our opinion, one of the major strengths of the study is that it provides rare data on the medial part of this large brain territory, including the posterior cingulate cortex and the precuneus. Neurological insults in these areas are uncommon for biological reasons, and electrostimulation procedures in clinical patients provide a unique opportunity to probe their functional significance. In view of its widespread connections and its central position in several large-scale networks (i.e. default mode network), this transmodal cortex (Mesulam et al. , 1998) is likely to participate in a wide-ranging set of high-level cognitive functions or processes, which are to date only suspected to originate through reverse inference from neuroimaging data. Current literature suggests a role in social cognition, autobiographic and topographical memory, auto-projective processes, and more generally in conscious self-awareness (e.g. mind wandering) (Cavanna et al. , 2006; Buckner et al. , 2008; Leech and Sharp, 2013 for reviews). On the other hand, functional connectivity MRI studies performed in neurological patients converge towards the idea that this region would be central in the network supporting consciousness (Vogt and Laurey, 2005; Boly et al. , 2008). In their study, the authors found that electrostimulation of the posterior cingulate cortex (16 and 34 effective stimulations were analysed in the left and right hemisphere, …}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sir, We have read with great interest the recent article by Balestrini et al. (2015) reporting a detailed cortical mapping of the parietal cortex. The work is remarkable in that it is based on the electrostimulation data from an impressive cohort of 172 patients with refractory focal epilepsy (419 cortical sites with a clinical response were unmasked), thus permitting authoritative conclusions about the functions of the different regions of the parietal cortex. In our opinion, one of the major strengths of the study is that it provides rare data on the medial part of this large brain territory, including the posterior cingulate cortex and the precuneus. Neurological insults in these areas are uncommon for biological reasons, and electrostimulation procedures in clinical patients provide a unique opportunity to probe their functional significance. In view of its widespread connections and its central position in several large-scale networks (i.e. default mode network), this transmodal cortex (Mesulam et al. , 1998) is likely to participate in a wide-ranging set of high-level cognitive functions or processes, which are to date only suspected to originate through reverse inference from neuroimaging data. Current literature suggests a role in social cognition, autobiographic and topographical memory, auto-projective processes, and more generally in conscious self-awareness (e.g. mind wandering) (Cavanna et al. , 2006; Buckner et al. , 2008; Leech and Sharp, 2013 for reviews). On the other hand, functional connectivity MRI studies performed in neurological patients converge towards the idea that this region would be central in the network supporting consciousness (Vogt and Laurey, 2005; Boly et al. , 2008). In their study, the authors found that electrostimulation of the posterior cingulate cortex (16 and 34 effective stimulations were analysed in the left and right hemisphere, … |
| 3. | Herbet, Guillaume; Maheu, Maxime; Costi, Emanuele; Lafargue, Gilles; Duffau, Hugues Mapping neuroplastic potential in brain-damaged patients Article de journal Dans: Brain, 139 (3), p. 829–844, 2016, ISSN: 0006-8950, 1460-2156. @article{herbet_mapping_2016, title = {Mapping neuroplastic potential in brain-damaged patients}, author = {Guillaume Herbet and Maxime Maheu and Emanuele Costi and Gilles Lafargue and Hugues Duffau}, url = {http://brain.oxfordjournals.org/content/139/3/829}, doi = {10.1093/brain/awv394}, issn = {0006-8950, 1460-2156}, year = {2016}, date = {2016-03-01}, urldate = {2016-02-29}, journal = {Brain}, volume = {139}, number = {3}, pages = {829--844}, abstract = {It is increasingly acknowledged that the brain is highly plastic. However, the anatomic factors governing the potential for neuroplasticity have hardly been investigated. To bridge this knowledge gap, we generated a probabilistic atlas of functional plasticity derived from both anatomic magnetic resonance imaging results and intraoperative mapping data on 231 patients having undergone surgery for diffuse, low-grade glioma. The atlas includes detailed level of confidence information and is supplemented with a series of comprehensive, connectivity-based cluster analyses. Our results show that cortical plasticity is generally high in the cortex (except in primary unimodal areas and in a small set of neural hubs) and rather low in connective tracts (especially associative and projection tracts). The atlas sheds new light on the topological organization of critical neural systems and may also be useful in predicting the likelihood of recovery (as a function of lesion topology) in various neuropathological conditions—a crucial factor in improving the care of brain-damaged patients.}, keywords = {}, pubstate = {published}, tppubtype = {article} } It is increasingly acknowledged that the brain is highly plastic. However, the anatomic factors governing the potential for neuroplasticity have hardly been investigated. To bridge this knowledge gap, we generated a probabilistic atlas of functional plasticity derived from both anatomic magnetic resonance imaging results and intraoperative mapping data on 231 patients having undergone surgery for diffuse, low-grade glioma. The atlas includes detailed level of confidence information and is supplemented with a series of comprehensive, connectivity-based cluster analyses. Our results show that cortical plasticity is generally high in the cortex (except in primary unimodal areas and in a small set of neural hubs) and rather low in connective tracts (especially associative and projection tracts). The atlas sheds new light on the topological organization of critical neural systems and may also be useful in predicting the likelihood of recovery (as a function of lesion topology) in various neuropathological conditions—a crucial factor in improving the care of brain-damaged patients. |
| 4. | Lemaitre, Anne-Laure; Luyat, Marion; Lafargue, Gilles Individuals with pronounced schizotypal traits are particularly successful in tickling themselves Article de journal Dans: Consciousness and Cognition, 41 , p. 64–71, 2016, ISSN: 1053-8100. @article{lemaitre_individuals_2016, title = {Individuals with pronounced schizotypal traits are particularly successful in tickling themselves}, author = {Anne-Laure Lemaitre and Marion Luyat and Gilles Lafargue}, url = {http://www.sciencedirect.com/science/article/pii/S1053810016300174}, doi = {10.1016/j.concog.2016.02.005}, issn = {1053-8100}, year = {2016}, date = {2016-02-01}, urldate = {2016-02-29}, journal = {Consciousness and Cognition}, volume = {41}, pages = {64--71}, abstract = {We assessed self-tickling sensations in a group of participants high in schizotypal traits (n = 27) and group of participants low in schizotypal traits (n = 27). The groups were formed by screening a pool of 397 students for extreme scores in the French version of the Schizotypal Personality Questionnaire. As observed in a previous study involving psychiatric people with auditory hallucinations and/or passivity experiences our results showed that self-applied tactile stimulations are felt to be more ticklish by healthy individuals high in schizotypal traits. In contrast, there were no significant intergroup differences in the mean tickle rating in the externally-produced tickling condition. Furthermore, more successful self-tickling was associated with more frequent self-reports of unusual perceptual experiences (such as supernatural experiences) and passivity experiences in particular (such as a feeling of being under the control of an outside force or power).}, keywords = {}, pubstate = {published}, tppubtype = {article} } We assessed self-tickling sensations in a group of participants high in schizotypal traits (n = 27) and group of participants low in schizotypal traits (n = 27). The groups were formed by screening a pool of 397 students for extreme scores in the French version of the Schizotypal Personality Questionnaire. As observed in a previous study involving psychiatric people with auditory hallucinations and/or passivity experiences our results showed that self-applied tactile stimulations are felt to be more ticklish by healthy individuals high in schizotypal traits. In contrast, there were no significant intergroup differences in the mean tickle rating in the externally-produced tickling condition. Furthermore, more successful self-tickling was associated with more frequent self-reports of unusual perceptual experiences (such as supernatural experiences) and passivity experiences in particular (such as a feeling of being under the control of an outside force or power). |
2015 |
|
| 5. | Herbet, Guillaume; Lafargue, Gilles; Almairac, Fabien; Moritz-Gasser, Sylvie; Bonnetblanc, François; Duffau, Hugues Disrupting the right pars opercularis with electrical stimulation frees the song: case report Article de journal Dans: Journal of Neurosurgery, 123 (6), p. 1401–1404, 2015, ISSN: 0022-3085. @article{herbet_disrupting_2015, title = {Disrupting the right pars opercularis with electrical stimulation frees the song: case report}, author = {Guillaume Herbet and Gilles Lafargue and Fabien Almairac and Sylvie Moritz-Gasser and François Bonnetblanc and Hugues Duffau}, url = {http://thejns.org/doi/abs/10.3171/2014.12.JNS141829}, doi = {10.3171/2014.12.JNS141829}, issn = {0022-3085}, year = {2015}, date = {2015-12-01}, urldate = {2016-02-29}, journal = {Journal of Neurosurgery}, volume = {123}, number = {6}, pages = {1401--1404}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
| 6. | Herbet, Guillaume; Lafargue, Gilles; Moritz-Gasser, Sylvie; Bonnetblanc, François; Duffau, Hugues Interfering with the neural activity of mirror-related frontal areas impairs mentalistic inferences Article de journal Dans: 220 (4), p. 2159–2169, 2015, ISSN: 1863-2653, 1863-2661. @article{herbet_interfering_2015, title = {Interfering with the neural activity of mirror-related frontal areas impairs mentalistic inferences}, author = {Guillaume Herbet and Gilles Lafargue and Sylvie Moritz-Gasser and François Bonnetblanc and Hugues Duffau}, url = {http://link.springer.com/article/10.1007/s00429-014-0777-x}, doi = {10.1007/s00429-014-0777-x}, issn = {1863-2653, 1863-2661}, year = {2015}, date = {2015-07-01}, urldate = {2016-02-29}, volume = {220}, number = {4}, pages = {2159--2169}, abstract = {According to recently proposed interactive dual-process theories, mentalizing abilities emerge from the coherent interaction between two physically distinct neural systems: (1) the mirror network, coding for the low-level embodied representations involved in pre-reflective sociocognitive processes and (2) the mentalizing network per se, which codes for higher level representations subtending the reflective attribution of psychological states. However, although the latest studies have shown that the core areas forming these two neurocognitive systems do indeed maintain effective connectivity during mentalizing, it is unclear whether an intact mirror system (and, more specifically, its anterior node, namely the posterior inferior frontal cortex) is a prerequisite for accurate mentalistic inferences. Intraoperative brain mapping via direct electrical stimulation offers a unique opportunity to address this issue. Electrical stimulation of the brain creates a “virtual” lesion, which provides functional information on well-defined parts of the cerebral cortex. In the present study, five patients were mapped in real time while they performed a mentalizing task. We found six responsive sites: four in the lateral part of the right pars opercularis and two in the dorsal part of the right pars triangularis. On the subcortical level, two additional sites were located within the white matter connectivity of the pars opercularis. Taken as a whole, our results suggest that the right inferior frontal cortex and its underlying axonal connectivity have a key role in mentalizing. Specifically, our findings support the hypothesis whereby transient, functional disruption of the mirror network influences higher order mentalistic inferences.}, keywords = {}, pubstate = {published}, tppubtype = {article} } According to recently proposed interactive dual-process theories, mentalizing abilities emerge from the coherent interaction between two physically distinct neural systems: (1) the mirror network, coding for the low-level embodied representations involved in pre-reflective sociocognitive processes and (2) the mentalizing network per se, which codes for higher level representations subtending the reflective attribution of psychological states. However, although the latest studies have shown that the core areas forming these two neurocognitive systems do indeed maintain effective connectivity during mentalizing, it is unclear whether an intact mirror system (and, more specifically, its anterior node, namely the posterior inferior frontal cortex) is a prerequisite for accurate mentalistic inferences. Intraoperative brain mapping via direct electrical stimulation offers a unique opportunity to address this issue. Electrical stimulation of the brain creates a “virtual” lesion, which provides functional information on well-defined parts of the cerebral cortex. In the present study, five patients were mapped in real time while they performed a mentalizing task. We found six responsive sites: four in the lateral part of the right pars opercularis and two in the dorsal part of the right pars triangularis. On the subcortical level, two additional sites were located within the white matter connectivity of the pars opercularis. Taken as a whole, our results suggest that the right inferior frontal cortex and its underlying axonal connectivity have a key role in mentalizing. Specifically, our findings support the hypothesis whereby transient, functional disruption of the mirror network influences higher order mentalistic inferences. |
| 7. | Herbet, Guillaume; Lafargue, Gilles; Moritz-Gasser, Sylvie; de Champfleur, Nicolas Menjot; Costi, Emanuele; Bonnetblanc, François; Duffau, Hugues A disconnection account of subjective empathy impairments in diffuse low-grade glioma patients Article de journal Dans: Neuropsychologia, 70 , p. 165–176, 2015, ISSN: 1873-3514. @article{herbet_disconnection_2015, title = {A disconnection account of subjective empathy impairments in diffuse low-grade glioma patients}, author = {Guillaume Herbet and Gilles Lafargue and Sylvie Moritz-Gasser and Nicolas Menjot de Champfleur and Emanuele Costi and François Bonnetblanc and Hugues Duffau}, doi = {10.1016/j.neuropsychologia.2015.02.015}, issn = {1873-3514}, year = {2015}, date = {2015-01-01}, journal = {Neuropsychologia}, volume = {70}, pages = {165--176}, abstract = {Human empathic experience is a multifaceted psychological construct which arises from functional integration of multiple neural networks. Despite accumulating knowledge about the cortical circuitry of empathy, almost nothing is known about the connectivity that may be concerned in conveying empathy-related neural information. To bridge this gap in knowledge, we studied dispositional empathy in a large-sized cohort of 107 patients who had undergone surgery for a diffuse low-grade glioma. The self-report questionnaire used enabled us to obtain a global measure of subjective empathy but also, importantly, to assess the two main components of empathy (cognitive and emotional). Data were processed by combining voxelwise and tractwise lesion-symptom analyses. Several major findings emerged from our analyses. First of all, topological voxelwise analyses were inconclusive. Conversely, tractwise multiple regression analyses, including all major associative white matter pathways as potential predictors, yielded to significant models explaining substantial part of the behavioural variance. Among the main results, we found that disconnection of the left cingulum bundle was a strong predictor of a low cognitive empathy (ptextbackslashtextless0.0005 Bonferroni-corrected). Similarly, we found that disconnection of the right uncinate fasciculus and the right inferior fronto-occipital fasciculus predicted, respectively, a low (ptextbackslashtextless0.05 Bonferroni-corrected) and a high (ptextbackslashtextless0.05 Bonferroni-corrected) subjective empathy. Finally, although we failed to relate emotional empathy to disruption of a specific tract, correlation analyses indicated a positive association between this component of empathy and the volumes of residual lesion infiltration in the right hemisphere (ptextbackslashtextless0.01). Taken as a whole, these findings provide key fundamental insights into the anatomical connectivity of empathy. They may help to better understand the pathophysiology of empathy impairments in pathological conditions characterized by abnormalities of long-range anatomical connectivity, such as autism spectrum disorders, schizophrenia and fronto-temporal dementia.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human empathic experience is a multifaceted psychological construct which arises from functional integration of multiple neural networks. Despite accumulating knowledge about the cortical circuitry of empathy, almost nothing is known about the connectivity that may be concerned in conveying empathy-related neural information. To bridge this gap in knowledge, we studied dispositional empathy in a large-sized cohort of 107 patients who had undergone surgery for a diffuse low-grade glioma. The self-report questionnaire used enabled us to obtain a global measure of subjective empathy but also, importantly, to assess the two main components of empathy (cognitive and emotional). Data were processed by combining voxelwise and tractwise lesion-symptom analyses. Several major findings emerged from our analyses. First of all, topological voxelwise analyses were inconclusive. Conversely, tractwise multiple regression analyses, including all major associative white matter pathways as potential predictors, yielded to significant models explaining substantial part of the behavioural variance. Among the main results, we found that disconnection of the left cingulum bundle was a strong predictor of a low cognitive empathy (ptextbackslashtextless0.0005 Bonferroni-corrected). Similarly, we found that disconnection of the right uncinate fasciculus and the right inferior fronto-occipital fasciculus predicted, respectively, a low (ptextbackslashtextless0.05 Bonferroni-corrected) and a high (ptextbackslashtextless0.05 Bonferroni-corrected) subjective empathy. Finally, although we failed to relate emotional empathy to disruption of a specific tract, correlation analyses indicated a positive association between this component of empathy and the volumes of residual lesion infiltration in the right hemisphere (ptextbackslashtextless0.01). Taken as a whole, these findings provide key fundamental insights into the anatomical connectivity of empathy. They may help to better understand the pathophysiology of empathy impairments in pathological conditions characterized by abnormalities of long-range anatomical connectivity, such as autism spectrum disorders, schizophrenia and fronto-temporal dementia. |
| 8. | Herbet, Guillaume; Lafargue, Gilles; Duffau, Hugues Rethinking voxel-wise lesion-deficit analysis: A new challenge for computational neuropsychology Article de journal Dans: Cortex, 64 , p. 413–416, 2015, ISSN: 1973-8102. @article{herbet_rethinking_2015, title = {Rethinking voxel-wise lesion-deficit analysis: A new challenge for computational neuropsychology}, author = {Guillaume Herbet and Gilles Lafargue and Hugues Duffau}, doi = {10.1016/j.cortex.2014.10.021}, issn = {1973-8102}, year = {2015}, date = {2015-01-01}, journal = {Cortex}, volume = {64}, pages = {413--416}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2014 |
|
| 9. | Herbet, Guillaume; Lafargue, Gilles; de Champfleur, Nicolas Menjot; Moritz-Gasser, Sylvie; le Bars, Emmanuelle; Bonnetblanc, François; Duffau, Hugues Disrupting posterior cingulate connectivity disconnects consciousness from the external environment Article de journal Dans: Neuropsychologia, 56 , p. 239–244, 2014, ISSN: 1873-3514. @article{herbet_disrupting_2014, title = {Disrupting posterior cingulate connectivity disconnects consciousness from the external environment}, author = {Guillaume Herbet and Gilles Lafargue and Nicolas Menjot de Champfleur and Sylvie Moritz-Gasser and Emmanuelle le Bars and François Bonnetblanc and Hugues Duffau}, doi = {10.1016/j.neuropsychologia.2014.01.020}, issn = {1873-3514}, year = {2014}, date = {2014-04-01}, journal = {Neuropsychologia}, volume = {56}, pages = {239--244}, abstract = {Neurophysiological and neuroimaging studies including both patients with disorders of consciousness and healthy subjects with modified states of consciousness suggest a crucial role of the medial posteroparietal cortex in conscious information processing. However no direct neuropsychological evidence supports this hypothesis and studies including patients with restricted lesions of this brain region are almost non-existent. Using direct intraoperative electrostimulations, we showed in a rare patient that disrupting the subcortical connectivity of the left posterior cingulate cortex (PCC) reliably induced a breakdown in conscious experience. This acute phenomenon was mainly characterized by a transient behavioral unresponsiveness with loss of external connectedness. In all cases, when he regained consciousness, the patient described himself as in dream, outside the operating room. This finding suggests that functional integrity of the PPC connectivity is necessary for maintaining consciousness of external environment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Neurophysiological and neuroimaging studies including both patients with disorders of consciousness and healthy subjects with modified states of consciousness suggest a crucial role of the medial posteroparietal cortex in conscious information processing. However no direct neuropsychological evidence supports this hypothesis and studies including patients with restricted lesions of this brain region are almost non-existent. Using direct intraoperative electrostimulations, we showed in a rare patient that disrupting the subcortical connectivity of the left posterior cingulate cortex (PCC) reliably induced a breakdown in conscious experience. This acute phenomenon was mainly characterized by a transient behavioral unresponsiveness with loss of external connectedness. In all cases, when he regained consciousness, the patient described himself as in dream, outside the operating room. This finding suggests that functional integrity of the PPC connectivity is necessary for maintaining consciousness of external environment. |
| 10. | Herbet, Guillaume; Lafargue, Gilles; Bonnetblanc, François; Moritz-Gasser, Sylvie; de Champfleur, Nicolas Menjot; Duffau, Hugues Inferring a dual-stream model of mentalizing from associative white matter fibres disconnection Article de journal Dans: Brain, 137 (Pt 3), p. 944–959, 2014, ISSN: 1460-2156. @article{herbet_inferring_2014, title = {Inferring a dual-stream model of mentalizing from associative white matter fibres disconnection}, author = {Guillaume Herbet and Gilles Lafargue and François Bonnetblanc and Sylvie Moritz-Gasser and Nicolas Menjot de Champfleur and Hugues Duffau}, doi = {10.1093/brain/awt370}, issn = {1460-2156}, year = {2014}, date = {2014-03-01}, journal = {Brain}, volume = {137}, number = {Pt 3}, pages = {944--959}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
| 11. | Herbet, Guillaume; Lafargue, Gilles; Moritz-Gasser, Sylvie; Bonnetblanc, François; Duffau, Hugues Interfering with the neural activity of mirror-related frontal areas impairs mentalistic inferences Article de journal Dans: Brain Struct Funct, p. 1–11, 2014, ISSN: 1863-2653, 1863-2661. @article{herbet_interfering_2014, title = {Interfering with the neural activity of mirror-related frontal areas impairs mentalistic inferences}, author = {Guillaume Herbet and Gilles Lafargue and Sylvie Moritz-Gasser and François Bonnetblanc and Hugues Duffau}, url = {http://link.springer.com/article/10.1007/s00429-014-0777-x}, doi = {10.1007/s00429-014-0777-x}, issn = {1863-2653, 1863-2661}, year = {2014}, date = {2014-01-01}, urldate = {2015-03-26}, journal = {Brain Struct Funct}, pages = {1--11}, abstract = {According to recently proposed interactive dual-process theories, mentalizing abilities emerge from the coherent interaction between two physically distinct neural systems: (1) the mirror network, coding for the low-level embodied representations involved in pre-reflective sociocognitive processes and (2) the mentalizing network per se, which codes for higher level representations subtending the reflective attribution of psychological states. However, although the latest studies have shown that the core areas forming these two neurocognitive systems do indeed maintain effective connectivity during mentalizing, it is unclear whether an intact mirror system (and, more specifically, its anterior node, namely the posterior inferior frontal cortex) is a prerequisite for accurate mentalistic inferences. Intraoperative brain mapping via direct electrical stimulation offers a unique opportunity to address this issue. Electrical stimulation of the brain creates a “virtual” lesion, which provides functional information on well-defined parts of the cerebral cortex. In the present study, five patients were mapped in real time while they performed a mentalizing task. We found six responsive sites: four in the lateral part of the right pars opercularis and two in the dorsal part of the right pars triangularis. On the subcortical level, two additional sites were located within the white matter connectivity of the pars opercularis. Taken as a whole, our results suggest that the right inferior frontal cortex and its underlying axonal connectivity have a key role in mentalizing. Specifically, our findings support the hypothesis whereby transient, functional disruption of the mirror network influences higher order mentalistic inferences.}, keywords = {}, pubstate = {published}, tppubtype = {article} } According to recently proposed interactive dual-process theories, mentalizing abilities emerge from the coherent interaction between two physically distinct neural systems: (1) the mirror network, coding for the low-level embodied representations involved in pre-reflective sociocognitive processes and (2) the mentalizing network per se, which codes for higher level representations subtending the reflective attribution of psychological states. However, although the latest studies have shown that the core areas forming these two neurocognitive systems do indeed maintain effective connectivity during mentalizing, it is unclear whether an intact mirror system (and, more specifically, its anterior node, namely the posterior inferior frontal cortex) is a prerequisite for accurate mentalistic inferences. Intraoperative brain mapping via direct electrical stimulation offers a unique opportunity to address this issue. Electrical stimulation of the brain creates a “virtual” lesion, which provides functional information on well-defined parts of the cerebral cortex. In the present study, five patients were mapped in real time while they performed a mentalizing task. We found six responsive sites: four in the lateral part of the right pars opercularis and two in the dorsal part of the right pars triangularis. On the subcortical level, two additional sites were located within the white matter connectivity of the pars opercularis. Taken as a whole, our results suggest that the right inferior frontal cortex and its underlying axonal connectivity have a key role in mentalizing. Specifically, our findings support the hypothesis whereby transient, functional disruption of the mirror network influences higher order mentalistic inferences. |
2013 |
|
| 12. | Lafargue, Gilles; Noël, Myriam; Luyat, Marion In the Elderly, Failure to Update Internal Models Leads to Over-Optimistic Predictions about Upcoming Actions Article de journal Dans: PLoS ONE, 8 (1), p. e51218, 2013. @article{lafargue_elderly_2013, title = {In the Elderly, Failure to Update Internal Models Leads to Over-Optimistic Predictions about Upcoming Actions}, author = {Gilles Lafargue and Myriam Noël and Marion Luyat}, url = {http://dx.doi.org/10.1371/journal.pone.0051218}, doi = {10.1371/journal.pone.0051218}, year = {2013}, date = {2013-01-01}, urldate = {2015-03-26}, journal = {PLoS ONE}, volume = {8}, number = {1}, pages = {e51218}, abstract = {Before an action is performed, the brain simulates the body's dynamic behavior in relation to the environment, estimates the possible outcomes and assesses the feasibility of potential actions. Here, we tested a hypothesis whereby age-related changes in sensorimotor abilities result in failure to update internal models of action in the elderly. Young and older adults were required to judge in advance whether or not they could stand on an inclined plane (Experiment 1). Relative to young adults, elderly adults overestimated their postural capabilities: although the two groups made similar feasibility judgments, elderly participants showed significantly worse postural performance levels. This tendency to overestimate their own ability persisted when elderly adults had to not only estimate the feasibility of an action but also endanger themselves by walking towards an obstacle that was too high for them to clear (Experiment 2). An age-related failure to update internal models may prompt the elderly to make over-optimistic predictions about upcoming actions. In turn, this may favor risky motor decision-making and promote falls.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Before an action is performed, the brain simulates the body's dynamic behavior in relation to the environment, estimates the possible outcomes and assesses the feasibility of potential actions. Here, we tested a hypothesis whereby age-related changes in sensorimotor abilities result in failure to update internal models of action in the elderly. Young and older adults were required to judge in advance whether or not they could stand on an inclined plane (Experiment 1). Relative to young adults, elderly adults overestimated their postural capabilities: although the two groups made similar feasibility judgments, elderly participants showed significantly worse postural performance levels. This tendency to overestimate their own ability persisted when elderly adults had to not only estimate the feasibility of an action but also endanger themselves by walking towards an obstacle that was too high for them to clear (Experiment 2). An age-related failure to update internal models may prompt the elderly to make over-optimistic predictions about upcoming actions. In turn, this may favor risky motor decision-making and promote falls. |
| 13. | Herbet, Guillaume; Lafargue, Gilles; Bonnetblanc, François; Moritz-Gasser, Sylvie; Duffau, Hugues Is the right frontal cortex really crucial in the mentalizing network? A longitudinal study in patients with a slow-growing lesion Article de journal Dans: Cortex, 49 (10), p. 2711–2727, 2013, ISSN: 1973-8102. @article{herbet_is_2013, title = {Is the right frontal cortex really crucial in the mentalizing network? A longitudinal study in patients with a slow-growing lesion}, author = {Guillaume Herbet and Gilles Lafargue and François Bonnetblanc and Sylvie Moritz-Gasser and Hugues Duffau}, doi = {10.1016/j.cortex.2013.08.003}, issn = {1973-8102}, year = {2013}, date = {2013-01-01}, journal = {Cortex}, volume = {49}, number = {10}, pages = {2711--2727}, abstract = {Assessing the subjective experience of others in terms of mental states, a brain function referred to as mentalizing, is achieved in the brain through a set of low-level perceptual and high-level inference-based processes. Because of its recurrent implication in fMRI studies, the right frontal cortex, especially in its inferolateral and dorsomesial parts, is posited to be a "core system" in the sustenance of these neurocognitive mechanisms. In this context, we reasoned that if the right frontal cortex is really crucial for mentalizing, its surgical resection, following diffuse low-grade glioma invasion, should induce irreversible impairments. To test this hypothesis, we designed a longitudinal experimental setup in which ten patients harboring a low-grade glioma in right frontal areas were assessed just before, immediately after and three months after a brain surgery. Two well-validated behavioral tasks, thought to evaluate both aspects of mentalizing, were administered. The results obtained provide evidence that widespread surgical excisions of the right prefrontal cortex do not induce a long-term worsening of both aspects of mentalizing, although some transitory effects are observed immediately after the surgery. They suggest also for the first time in the same sample of patients a possible double functional dissociation between low-level perceptual (posterior inferolateral prefrontal) and high-level inference-based (dorsomesial prefrontal) mentalizing processes. This overall finding challenges the traditional view according to which the right frontal cortex is an "essential cortical node" in the mentalizing network since it might be expected that massive surgical excisions of this brain area would have induced more definitive impairments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Assessing the subjective experience of others in terms of mental states, a brain function referred to as mentalizing, is achieved in the brain through a set of low-level perceptual and high-level inference-based processes. Because of its recurrent implication in fMRI studies, the right frontal cortex, especially in its inferolateral and dorsomesial parts, is posited to be a "core system" in the sustenance of these neurocognitive mechanisms. In this context, we reasoned that if the right frontal cortex is really crucial for mentalizing, its surgical resection, following diffuse low-grade glioma invasion, should induce irreversible impairments. To test this hypothesis, we designed a longitudinal experimental setup in which ten patients harboring a low-grade glioma in right frontal areas were assessed just before, immediately after and three months after a brain surgery. Two well-validated behavioral tasks, thought to evaluate both aspects of mentalizing, were administered. The results obtained provide evidence that widespread surgical excisions of the right prefrontal cortex do not induce a long-term worsening of both aspects of mentalizing, although some transitory effects are observed immediately after the surgery. They suggest also for the first time in the same sample of patients a possible double functional dissociation between low-level perceptual (posterior inferolateral prefrontal) and high-level inference-based (dorsomesial prefrontal) mentalizing processes. This overall finding challenges the traditional view according to which the right frontal cortex is an "essential cortical node" in the mentalizing network since it might be expected that massive surgical excisions of this brain area would have induced more definitive impairments. |
2012 |
|
| 14. | Guardia, Dewi; Conversy, Léa; Jardri, Renaud; Lafargue, Gilles; Thomas, Pierre; Dodin, Vincent; Cottencin, Olivier; Luyat, Marion Imagining one's own and someone else's body actions: dissociation in anorexia nervosa Article de journal Dans: PLoS ONE, 7 (8), p. e43241, 2012, ISSN: 1932-6203. @article{guardia_imagining_2012, title = {Imagining one's own and someone else's body actions: dissociation in anorexia nervosa}, author = {Dewi Guardia and Léa Conversy and Renaud Jardri and Gilles Lafargue and Pierre Thomas and Vincent Dodin and Olivier Cottencin and Marion Luyat}, doi = {10.1371/journal.pone.0043241}, issn = {1932-6203}, year = {2012}, date = {2012-01-01}, journal = {PLoS ONE}, volume = {7}, number = {8}, pages = {e43241}, abstract = {BACKGROUND: Patients with anorexia nervosa (AN) usually report feeling larger than they really are. This body overestimation appears to be related not only to the patient's body image but also to an abnormal representation of the body in action. In previous work on a body-scaled anticipation task, anorexic patients judged that they could not pass through a door-like aperture even when it was easily wide enough–suggesting the involvement of the body schema. In the present study, we sought to establish whether this erroneous judgment about action is specifically observed when it concerns one's own body or whether it is symptomatic of a general impairment in perceptual discrimination. METHODS: Twenty-five anorexic participants and 25 control participants were presented with a door-like aperture. They had to judge whether or not the aperture was wide enough for them to pass through (i.e. first-person perspective, 1PP) and for another person present in the testing room to pass through (i.e. third-person perspective, 3PP). RESULTS: We observed a higher passability ratio (i.e. the critical aperture size to shoulder width ratio) in AN patients for 1PP but not for 3PP. Moreover, the magnitude of the passability ratio was positively correlated not only with the extent of the patient's body and eating concerns but also with the body weight prior to disease onset. Our results suggest that body overestimation can affect judgments about the capacity for action but only when they concern the patient's own body. This could be related to impairments of the overall network involved in the emergence of the body schema and in one's own perspective judgments. CONCLUSION: Overestimation of the body schema might occur because the central nervous system has not updated the new, emaciated body, with maintenance of an incorrect representation based on the patient's pre-AN body dimensions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } BACKGROUND: Patients with anorexia nervosa (AN) usually report feeling larger than they really are. This body overestimation appears to be related not only to the patient's body image but also to an abnormal representation of the body in action. In previous work on a body-scaled anticipation task, anorexic patients judged that they could not pass through a door-like aperture even when it was easily wide enough–suggesting the involvement of the body schema. In the present study, we sought to establish whether this erroneous judgment about action is specifically observed when it concerns one's own body or whether it is symptomatic of a general impairment in perceptual discrimination. METHODS: Twenty-five anorexic participants and 25 control participants were presented with a door-like aperture. They had to judge whether or not the aperture was wide enough for them to pass through (i.e. first-person perspective, 1PP) and for another person present in the testing room to pass through (i.e. third-person perspective, 3PP). RESULTS: We observed a higher passability ratio (i.e. the critical aperture size to shoulder width ratio) in AN patients for 1PP but not for 3PP. Moreover, the magnitude of the passability ratio was positively correlated not only with the extent of the patient's body and eating concerns but also with the body weight prior to disease onset. Our results suggest that body overestimation can affect judgments about the capacity for action but only when they concern the patient's own body. This could be related to impairments of the overall network involved in the emergence of the body schema and in one's own perspective judgments. CONCLUSION: Overestimation of the body schema might occur because the central nervous system has not updated the new, emaciated body, with maintenance of an incorrect representation based on the patient's pre-AN body dimensions. |
2011 |
|
| 15. | Cléry-Melin, Marie-Laure; Schmidt, Liane; Lafargue, Gilles; Baup, Nicolas; Fossati, Philippe; Pessiglione, Mathias Why don't you try harder? An investigation of effort production in major depression Article de journal Dans: PLoS ONE, 6 (8), p. e23178, 2011, ISSN: 1932-6203. @article{clery-melin_why_2011, title = {Why don't you try harder? An investigation of effort production in major depression}, author = {Marie-Laure Cléry-Melin and Liane Schmidt and Gilles Lafargue and Nicolas Baup and Philippe Fossati and Mathias Pessiglione}, doi = {10.1371/journal.pone.0023178}, issn = {1932-6203}, year = {2011}, date = {2011-01-01}, journal = {PLoS ONE}, volume = {6}, number = {8}, pages = {e23178}, abstract = {Depression is mainly characterized as an emotional disorder, associated with reduced approach behavior. It remains unclear whether the difficulty in energising behavior relates to abnormal emotional states or to a flattened response to potential rewards, as suggested by several neuroimaging studies. Here, we aimed to demonstrate a specific incentive motivation deficit in major depression, independent of patients' emotional state. We employed a behavioral paradigm designed to measure physical effort in response to both emotional modulation and incentive motivation. Patients did exert more effort following emotionally arousing pictures (whether positive or negative) but not for higher monetary incentives, contrary to healthy controls. These results show that emotional and motivational sources of effort production are dissociable in pathological conditions. In addition, patients' ratings of perceived effort increased for high incentives, whereas controls' ratings were decreased. Thus, depressed patients objectively behave as if they do not want to gain larger rewards, but subjectively feel that they try harder. We suggest that incentive motivation impairment is a core deficit of major depression, which may render everyday tasks abnormally effortful for patients.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Depression is mainly characterized as an emotional disorder, associated with reduced approach behavior. It remains unclear whether the difficulty in energising behavior relates to abnormal emotional states or to a flattened response to potential rewards, as suggested by several neuroimaging studies. Here, we aimed to demonstrate a specific incentive motivation deficit in major depression, independent of patients' emotional state. We employed a behavioral paradigm designed to measure physical effort in response to both emotional modulation and incentive motivation. Patients did exert more effort following emotionally arousing pictures (whether positive or negative) but not for higher monetary incentives, contrary to healthy controls. These results show that emotional and motivational sources of effort production are dissociable in pathological conditions. In addition, patients' ratings of perceived effort increased for high incentives, whereas controls' ratings were decreased. Thus, depressed patients objectively behave as if they do not want to gain larger rewards, but subjectively feel that they try harder. We suggest that incentive motivation impairment is a core deficit of major depression, which may render everyday tasks abnormally effortful for patients. |
| 16. | Jardri, Renaud; Pins, Delphine; Lafargue, Gilles; Very, Etienne; Ameller, Aurély; Delmaire, Christine; Thomas, Pierre Increased overlap between the brain areas involved in self-other distinction in schizophrenia Article de journal Dans: PLoS ONE, 6 (3), p. e17500, 2011, ISSN: 1932-6203. @article{jardri_increased_2011, title = {Increased overlap between the brain areas involved in self-other distinction in schizophrenia}, author = {Renaud Jardri and Delphine Pins and Gilles Lafargue and Etienne Very and Aurély Ameller and Christine Delmaire and Pierre Thomas}, doi = {10.1371/journal.pone.0017500}, issn = {1932-6203}, year = {2011}, date = {2011-01-01}, journal = {PLoS ONE}, volume = {6}, number = {3}, pages = {e17500}, abstract = {Self-awareness impairments are frequently mentioned as being responsible for the positive symptoms of schizophrenia spectrum disorders. However, the neural correlates of self-other distinction in this pathology are still poorly understood. In the present study, we developed an fMRI procedure in order to examine self-other distinction during speech exchange situations. Fifteen subjects with schizophrenia were compared to 15 matched controls. The results revealed an increased overlap between the self and non-self cortical maps in schizophrenia, in the medial frontal and medial parietal cortices, as well as in the right middle temporal cortex and the right inferior parietal lobule. Moreover, these neural structures showed less BOLD amplitude differences between the self and non-self conditions in the patients. These activation patterns were judged to be independent of mirror-like properties, familiarity or body-ownership processing. Significantly, the increase in the right IPL signal was found to correlate positively with the severity of first-rank symptoms, and thus could be considered a "state-marker" of schizophrenia, whereas temporal and medial parieto-frontal differences appear to be "trait-markers" of the disease. Such an increased overlap between self and non-self cortical maps might be considered a neuro-physiological signature of the well established self-awareness impairment in people suffering from schizophrenia.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Self-awareness impairments are frequently mentioned as being responsible for the positive symptoms of schizophrenia spectrum disorders. However, the neural correlates of self-other distinction in this pathology are still poorly understood. In the present study, we developed an fMRI procedure in order to examine self-other distinction during speech exchange situations. Fifteen subjects with schizophrenia were compared to 15 matched controls. The results revealed an increased overlap between the self and non-self cortical maps in schizophrenia, in the medial frontal and medial parietal cortices, as well as in the right middle temporal cortex and the right inferior parietal lobule. Moreover, these neural structures showed less BOLD amplitude differences between the self and non-self conditions in the patients. These activation patterns were judged to be independent of mirror-like properties, familiarity or body-ownership processing. Significantly, the increase in the right IPL signal was found to correlate positively with the severity of first-rank symptoms, and thus could be considered a "state-marker" of schizophrenia, whereas temporal and medial parieto-frontal differences appear to be "trait-markers" of the disease. Such an increased overlap between self and non-self cortical maps might be considered a neuro-physiological signature of the well established self-awareness impairment in people suffering from schizophrenia. |
2010 |
|
| 17. | Schmidt, Liane; Palminteri, Stefano; Lafargue, Gilles; Pessiglione, Mathias Splitting motivation: unilateral effects of subliminal incentives Article de journal Dans: Psychol Sci, 21 (7), p. 977–983, 2010, ISSN: 1467-9280. @article{schmidt_splitting_2010, title = {Splitting motivation: unilateral effects of subliminal incentives}, author = {Liane Schmidt and Stefano Palminteri and Gilles Lafargue and Mathias Pessiglione}, doi = {10.1177/0956797610372636}, issn = {1467-9280}, year = {2010}, date = {2010-07-01}, journal = {Psychol Sci}, volume = {21}, number = {7}, pages = {977--983}, abstract = {Motivation is generally understood to denote the strength of a person's desire to attain a goal. Here we challenge this view of motivation as a person-level concept, in a study that targeted subliminal incentives to only one half of the human brain. Participants in the study squeezed a handgrip to win the greatest fraction possible of each subliminal incentive, which materialized as a coin image flashed in one visual hemifield. Motivation effects (i.e., more force exerted when the incentive was higher) were observed only for the hand controlled by the stimulated brain hemisphere. These results show that in the absence of conscious control, one brain hemisphere, and hence one side of the body, can be motivated independently of the other.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Motivation is generally understood to denote the strength of a person's desire to attain a goal. Here we challenge this view of motivation as a person-level concept, in a study that targeted subliminal incentives to only one half of the human brain. Participants in the study squeezed a handgrip to win the greatest fraction possible of each subliminal incentive, which materialized as a coin image flashed in one visual hemifield. Motivation effects (i.e., more force exerted when the incentive was higher) were observed only for the hand controlled by the stimulated brain hemisphere. These results show that in the absence of conscious control, one brain hemisphere, and hence one side of the body, can be motivated independently of the other. |
| 18. | Guardia, Dewi; Lafargue, Gilles; Thomas, Pierre; Dodin, Vincent; Cottencin, Olivier; Luyat, Marion Anticipation of body-scaled action is modified in anorexia nervosa Article de journal Dans: Neuropsychologia, 48 (13), p. 3961–3966, 2010, ISSN: 1873-3514. @article{guardia_anticipation_2010, title = {Anticipation of body-scaled action is modified in anorexia nervosa}, author = {Dewi Guardia and Gilles Lafargue and Pierre Thomas and Vincent Dodin and Olivier Cottencin and Marion Luyat}, doi = {10.1016/j.neuropsychologia.2010.09.004}, issn = {1873-3514}, year = {2010}, date = {2010-01-01}, journal = {Neuropsychologia}, volume = {48}, number = {13}, pages = {3961--3966}, abstract = {Patients with anorexia nervosa frequently believe they are larger than they really are. The precise nature of this bias is not known: is it a false belief related to the patient's aesthetic and emotional attitudes towards her body? Or could it also reflect abnormal processing of the representation of the body in action? We tested this latter hypothesis by using a body-scaled action-anticipation task in which 25 anorexics and 25 control participants had to judge whether or not an aperture was wide enough for them to pass through. The anticipation of body-scaled action was severely disturbed in anorexic patients; they judged that they could not pass through an aperture, even when it was wide enough (i.e. they behave as if their body was larger than in reality). The abnormally high "passability ratio" (the critical aperture size to shoulder width ratio) was also correlated with the duration of illness and the degree of body concern/dissatisfaction. Our results suggest that body size overestimation in anorexia nervosa is not solely due to psycho-affective factors but rather suggest impaired neural processing of body dimensions that might take its source in parietal networks.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Patients with anorexia nervosa frequently believe they are larger than they really are. The precise nature of this bias is not known: is it a false belief related to the patient's aesthetic and emotional attitudes towards her body? Or could it also reflect abnormal processing of the representation of the body in action? We tested this latter hypothesis by using a body-scaled action-anticipation task in which 25 anorexics and 25 control participants had to judge whether or not an aperture was wide enough for them to pass through. The anticipation of body-scaled action was severely disturbed in anorexic patients; they judged that they could not pass through an aperture, even when it was wide enough (i.e. they behave as if their body was larger than in reality). The abnormally high "passability ratio" (the critical aperture size to shoulder width ratio) was also correlated with the duration of illness and the degree of body concern/dissatisfaction. Our results suggest that body size overestimation in anorexia nervosa is not solely due to psycho-affective factors but rather suggest impaired neural processing of body dimensions that might take its source in parietal networks. |
| 19. | Schmidt, Liane; Palminteri, Stefano; Lafargue, Gilles; Pessiglione, Mathias Splitting motivation: unilateral effects of subliminal incentives Article de journal Dans: Psychol Sci, 21 (7), p. 977–983, 2010, ISSN: 1467-9280. @article{schmidt_splitting_2010-1, title = {Splitting motivation: unilateral effects of subliminal incentives}, author = {Liane Schmidt and Stefano Palminteri and Gilles Lafargue and Mathias Pessiglione}, doi = {10.1177/0956797610372636}, issn = {1467-9280}, year = {2010}, date = {2010-01-01}, journal = {Psychol Sci}, volume = {21}, number = {7}, pages = {977--983}, abstract = {Motivation is generally understood to denote the strength of a person's desire to attain a goal. Here we challenge this view of motivation as a person-level concept, in a study that targeted subliminal incentives to only one half of the human brain. Participants in the study squeezed a handgrip to win the greatest fraction possible of each subliminal incentive, which materialized as a coin image flashed in one visual hemifield. Motivation effects (i.e., more force exerted when the incentive was higher) were observed only for the hand controlled by the stimulated brain hemisphere. These results show that in the absence of conscious control, one brain hemisphere, and hence one side of the body, can be motivated independently of the other.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Motivation is generally understood to denote the strength of a person's desire to attain a goal. Here we challenge this view of motivation as a person-level concept, in a study that targeted subliminal incentives to only one half of the human brain. Participants in the study squeezed a handgrip to win the greatest fraction possible of each subliminal incentive, which materialized as a coin image flashed in one visual hemifield. Motivation effects (i.e., more force exerted when the incentive was higher) were observed only for the hand controlled by the stimulated brain hemisphere. These results show that in the absence of conscious control, one brain hemisphere, and hence one side of the body, can be motivated independently of the other. |
| 20. | Lafargue, Gilles L’expérience subjective de l’effort volontaire dans la schizophrénie : approche neurophénoménologique Article de journal Dans: L'Évolution Psychiatrique, 75 (3), p. 421–433, 2010, ISSN: 0014-3855. @article{lafargue_lexperience_2010, title = {L’expérience subjective de l’effort volontaire dans la schizophrénie : approche neurophénoménologique}, author = {Gilles Lafargue}, url = {http://www.sciencedirect.com/science/article/pii/S001438551000068X}, doi = {10.1016/j.evopsy.2010.06.007}, issn = {0014-3855}, year = {2010}, date = {2010-01-01}, urldate = {2015-03-26}, journal = {L'Évolution Psychiatrique}, volume = {75}, number = {3}, pages = {421--433}, abstract = {Résumé Les croyances délirantes sont, avec les hallucinations, les symptômes les plus caractéristiques de la schizophrénie. Elles sont dites délirantes dans la mesure où elles sont bizarres, irrationnelles et difficilement compréhensibles dans les contextes sociaux et culturels dans lesquels elles émergent. Pourquoi de nombreux patients schizophrènes en viennent-ils à croire, à un moment ou à un autre de leur maladie, que leur pensée et leur corps sont contrôlés par des forces extérieures à leur propre volonté ? Un trouble spécifique de l’expérience consciente de la volonté d’agir, dû à un fonctionnement anormal de circuits neuraux frontopariétal, semble être à l’origine de la formation et du maintien de ce type de croyances erronées. Delusional beliefs are – with hallucinations – the most characteristic symptoms of schizophrenia. They are delusional in the sense that they are bizarre, irrational and not understandable in the social and cultural contexts where they emerge. Why do many people with schizophrenia come to believe they are controlled by forces external to their own will? A specific anomaly of the conscious experience of the will to act, due to abnormal neural processing of frontoparietal networks, seems to be at the origin of the formation and maintaining of such false beliefs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Résumé Les croyances délirantes sont, avec les hallucinations, les symptômes les plus caractéristiques de la schizophrénie. Elles sont dites délirantes dans la mesure où elles sont bizarres, irrationnelles et difficilement compréhensibles dans les contextes sociaux et culturels dans lesquels elles émergent. Pourquoi de nombreux patients schizophrènes en viennent-ils à croire, à un moment ou à un autre de leur maladie, que leur pensée et leur corps sont contrôlés par des forces extérieures à leur propre volonté ? Un trouble spécifique de l’expérience consciente de la volonté d’agir, dû à un fonctionnement anormal de circuits neuraux frontopariétal, semble être à l’origine de la formation et du maintien de ce type de croyances erronées. Delusional beliefs are – with hallucinations – the most characteristic symptoms of schizophrenia. They are delusional in the sense that they are bizarre, irrational and not understandable in the social and cultural contexts where they emerge. Why do many people with schizophrenia come to believe they are controlled by forces external to their own will? A specific anomaly of the conscious experience of the will to act, due to abnormal neural processing of frontoparietal networks, seems to be at the origin of the formation and maintaining of such false beliefs. |
2009 |
|
| 21. | Lafargue, G Peut-on se chatouiller soi-même ? Article de journal Dans: Pour la Science, (380), 2009. @article{lafargue_peut-se_2009, title = {Peut-on se chatouiller soi-même ?}, author = {G Lafargue}, url = {http://www.pourlascience.fr/ewb_pages/a/article-peut-on-se-chatouiller-soi-meme-22371.php}, year = {2009}, date = {2009-06-01}, urldate = {2015-03-26}, journal = {Pour la Science}, number = {380}, abstract = {Oui, à condition que l'on arrive à leurrer le mécanisme cérébral qui prédit les conséquences sensorielles des actions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Oui, à condition que l'on arrive à leurrer le mécanisme cérébral qui prédit les conséquences sensorielles des actions. |
| 22. | Lafargue, Gilles; Franck, Nicolas Effort awareness and sense of volition in schizophrenia Article de journal Dans: Conscious Cogn, 18 (1), p. 277–289, 2009, ISSN: 1090-2376. @article{lafargue_effort_2009, title = {Effort awareness and sense of volition in schizophrenia}, author = {Gilles Lafargue and Nicolas Franck}, doi = {10.1016/j.concog.2008.05.004}, issn = {1090-2376}, year = {2009}, date = {2009-03-01}, journal = {Conscious Cogn}, volume = {18}, number = {1}, pages = {277--289}, abstract = {Contemporary experimental research has emphasised the role of centrally generated signals arising from premotor areas in voluntary muscular force perception. It is therefore generally accepted that judgements of force are based on a central sense, known as the sense of effort, rather than on a sense of intra-muscular tension. Interestingly, the concept of effort is also present in the classical philosophy: to the French philosopher Maine de Biran [Maine de Biran (1805). Mémoire sur la décomposition de la pensée (Tome III), Vrin, Paris (1963)], the sense of effort is the fundamental component of self-experience, the landmark of the exercise of the will. In the present review, after a presentation of the nature and neurophysiological bases of effort sensation, we will examine its possible involvement in the neurocognitive process of agency. We will further focus on delusions of alien control in schizophrenic patients. Experimental data suggest that these patients have an abnormal awareness of effort caused by cerebral anomalies in the frontal and parietal lobes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Contemporary experimental research has emphasised the role of centrally generated signals arising from premotor areas in voluntary muscular force perception. It is therefore generally accepted that judgements of force are based on a central sense, known as the sense of effort, rather than on a sense of intra-muscular tension. Interestingly, the concept of effort is also present in the classical philosophy: to the French philosopher Maine de Biran [Maine de Biran (1805). Mémoire sur la décomposition de la pensée (Tome III), Vrin, Paris (1963)], the sense of effort is the fundamental component of self-experience, the landmark of the exercise of the will. In the present review, after a presentation of the nature and neurophysiological bases of effort sensation, we will examine its possible involvement in the neurocognitive process of agency. We will further focus on delusions of alien control in schizophrenic patients. Experimental data suggest that these patients have an abnormal awareness of effort caused by cerebral anomalies in the frontal and parietal lobes. |
| 23. | Palminteri, Stefano; Boraud, Thomas; Lafargue, Gilles; Dubois, Bruno; Pessiglione, Mathias Brain hemispheres selectively track the expected value of contralateral options Article de journal Dans: J. Neurosci., 29 (43), p. 13465–13472, 2009, ISSN: 1529-2401. @article{palminteri_brain_2009, title = {Brain hemispheres selectively track the expected value of contralateral options}, author = {Stefano Palminteri and Thomas Boraud and Gilles Lafargue and Bruno Dubois and Mathias Pessiglione}, doi = {10.1523/JNEUROSCI.1500-09.2009}, issn = {1529-2401}, year = {2009}, date = {2009-01-01}, journal = {J. Neurosci.}, volume = {29}, number = {43}, pages = {13465--13472}, abstract = {A main focus in economics is on binary choice situations, in which human agents have to choose between two alternative options. The classical view is that decision making consists of valuating each option, comparing the two expected values, and selecting the higher one. Some neural correlates of option values have been described in animals, but little is known about how they are represented in the human brain: are they integrated into a single center or distributed over different areas? To address this issue, we examined whether the expected values of two options, which were cued by visual symbols and chosen with either the left or right hand, could be distinguished using functional magnetic resonance imaging. The two options were linked to monetary rewards through probabilistic contingencies that subjects had to learn so as to maximize payoff. Learning curves were fitted with a standard computational model that updates, on a trial-by-trial basis, the value of the chosen option in proportion to a reward prediction error. Results show that during learning, left and right option values were specifically expressed in the contralateral ventral prefrontal cortex, regardless of the upcoming choice. We therefore suggest that expected values are represented in a distributed manner that respects the topography of the brain systems elicited by the available options.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A main focus in economics is on binary choice situations, in which human agents have to choose between two alternative options. The classical view is that decision making consists of valuating each option, comparing the two expected values, and selecting the higher one. Some neural correlates of option values have been described in animals, but little is known about how they are represented in the human brain: are they integrated into a single center or distributed over different areas? To address this issue, we examined whether the expected values of two options, which were cued by visual symbols and chosen with either the left or right hand, could be distinguished using functional magnetic resonance imaging. The two options were linked to monetary rewards through probabilistic contingencies that subjects had to learn so as to maximize payoff. Learning curves were fitted with a standard computational model that updates, on a trial-by-trial basis, the value of the chosen option in proportion to a reward prediction error. Results show that during learning, left and right option values were specifically expressed in the contralateral ventral prefrontal cortex, regardless of the upcoming choice. We therefore suggest that expected values are represented in a distributed manner that respects the topography of the brain systems elicited by the available options. |
page mise à jour le 2017-09-04