Research subject

We are a multidisciplinary research team gathering scientists from various domains: mathematics, medical imaging, nuclear medicine, signal processing, psychiatry and cognitive neurosciences. Our research attempts at understanding the cognitive, behavioural, genetic, and brain morphological/functional underpinnings of the human brain hemispheric specialization (HS).

Hemispheric specialization is a relationship between a cognitive function and a set of cerebral structures of a given hemisphere. It includes both the hosting of specialized networks that have unique functional properties and mechanisms that allow inter-hemispheric coordination necessary for effective cognitive processing. The observations of patients with brain lesions since that of Broca in 1860 showed that the peculiarity of the SH of Humans is its low variability. For example more than 90% of the human beings have language functions in the left hemisphere and visuo-spatial attention by the right hemisphere. Studies of people with developmental diseases that cause language abnormalities such as dysphasia or dyslexia have shown that these subjects are less asymmetrical at the brain level. This is also the case in certain psychoses such as schizophrenia. But the origin and the factors of variability the HS remains poorly known in part because of its low variability.

We work on neuroimaging cohorts of healthy volunteers in order:

1-to determine how the two hemispheres are differentially involved in a given task, how HS  variability is associated with cognitive functioning and how gene shapes HS. To this aims, we have acquired the Brain Imaging of Lateralization by the BIL&GIN (Brain Imaging Lateralization & GIN) database of 453 healthy participants;

2- to characterize the neural support of the late maturational stages of healthy brain within the frame of the i-Share cohort of students’ health conducted by C Tzourio. We are currently acquiring brain anatomical and functional images in 2,000 students of Bordeaux University.

The GIN research activity revolves around five thematic axes :

  • Exploring the rules for the setting up of the different hemispheric specializations.
  • Hemispheric specialization and cognitive skills.
  • Comparison of left and right hemispheres integrating anatomical, resting-state and task-induced related organization.
  • Unmasking cognitive networks and their lateralization from intrinsic connectivity.
  • Genetics of brain lateralization (Multiple collaborations with Dana, ENIGMA consortium; C Francks, MPI Nijmegen; Ml Carreiras, BCBL, San Sebastian; H Adams, Erasmus Univ. Rotterdam).

 

Research axes

How does the hemispherical cerebral organization of cognitive functions take place? How does it happen that some people atypically shelter language in their right hemisphere? Is hemispheric lateralization necessary for optimal cerebral and cognitive functioning? If yes, for which functions? Are the  subjects atypical for a given also have atypical organization of other cognitive networks? Are anatomical asymmetries markers of functional asymmetries? Can we determine non-invasively the lateralization for the language of an individual? Do atypical individuals have genetic features that explain their change in lateralization? To answer these questions we combine anatomical, functional neuroimaging, connectivity measures, behavioral data, genotyping and databasing.

A complete map of the cerebral connections, the connectome, is required for interpreting measurements of the signals transmitted between neurons. In the human brain, these signals travel in a complex network of 100 billion or so neurons, each of which is connected to 10,000 others, through the axons which constitute the bundles of white matter fibers. Identifying these pathways of connections is a first approach to establish such a map. Another approach, known as functional connectivity, is to follow the spontaneous activity synchronized between the groups of neurons.
The combination of these two approaches is possible thanks to the advances of both anatomical and functional Magnetic Resonance Imaging (MRI) technologies. Our project deals with this new framework of the modern neuroscience, the connectomics, which examines the anatomical organization and the functioning of the brain through the connectome to relate it with the cognitive functioning.

Population neuroimaging aims to identify the different potential sources of brain variability and to measure the size of their effects and their interaction. It is our area of research whose contributions are important from both cognitive, societal, and medical perspectives. Population neuroimaging has an important role to play in face of the many questions and preconceptions that give rise to particularly hot debates such as for example the relationship between brain and mind, the respective roles of genes and environment on the morphology, organization, functional architecture, and performances of our brains, whether or not a sexual brain exists, the differences between left-handers and right-handers, etc. Finally, from medical and healthcare perspectives, understanding what is at the source of cerebral variability and quantifying the limits of its “normality” are of course fundamental to progress on the definition, diagnosis and development of new therapeutic approaches to cerebral diseases.

More information about the GIN, its history, its news… >>>

Complete bibliography >>>

Latest publications

Search Results --> Url version détaillée , Url version formatée
Criteria : Author : "Nathalie,Tzourio-Mazoyer;Bernard,Mazoyer;Laurent,Petit;Fabrice,Crivello;Marc,Joliot;Emmanuel,Mellet;Laure,Zago;Gael,Jobard;Isabelle,Hesling", Publication type : "('ART')"
Number of occurrences founded : 181.

titre
Brain connections derived from diffusion MRI tractography can be highly anatomically accurate—if we know where white matter pathways start, where they end, and where they do not go
auteur
Kurt Schilling, Laurent Petit, Francois Rheault, Samuel Remedios, Carlo Pierpaoli, Adam Anderson, Bennett A Landman, Maxime Descoteaux
article
Brain Structure and Function, Springer Verlag, 2020, 225 (8), pp.2387-2402. ⟨10.1007/s00429-020-02129-z⟩
identifiant
hal-03004295
titre
A new method for accurate in vivo mapping of human brain connections using microstructural and anatomical information
auteur
Simona Schiavi, Mario Ocampo-Pineda, Muhamed Barakovic, Laurent Petit, Maxime Descoteaux, Jean-Philippe Thiran, Alessandro Daducci
article
Science Advances , American Association for the Advancement of Science (AAAS), 2020, 6 (31), pp.eaba8245. ⟨10.1126/sciadv.aba8245⟩
identifiant
hal-03003996
titre
Age-Related Changes of Peak Width Skeletonized Mean Diffusivity (PSMD) Across the Adult Lifespan: A Multi-Cohort Study
auteur
Gregory Beaudet, Ami Tsuchida, Laurent Petit, Christophe Tzourio, Svenja Caspers, Jan Schreiber, Zdenka Pausova, Yash Patel, Tomas Paus, Reinhold Schmidt, Lukas Pirpamer, Perminder Sachdev, Henry Brodaty, Nicole Kochan, Julian Trollor, Wei Wen, Nicola Armstrong, Ian Deary, Mark Bastin, Joanna Wardlaw, Susana Muñoz Maniega, A. Veronica Witte, Arno Villringer, Marco Duering, Stephanie Debette, Bernard Mazoyer
article
Frontiers in Psychiatry, Frontiers, 2020, 11, ⟨10.3389/fpsyt.2020.00342⟩
identifiant
hal-02904246
titre
Age-Related Changes of Peak Width Skeletonized Mean Diffusivity (PSMD) Across the Adult Lifespan: A Multi-Cohort Study
auteur
Gregory Beaudet, Ami Tsuchida, Laurent Petit, Christophe Tzourio, Svenja Caspers, Jan Schreiber, Zdenka Pausova, Yash Patel, Tomáš Paus, Reinhold Schmidt, Lukas Pirpamer, Perminder Sachdev, Henry Brodaty, Nicole Kochan, Julian Trollor, Wei Wen, Nicola J Armstrong, Ian J Deary, Mark E Bastin, Joanna M Wardlaw, Susana Munoz Maniega, Anja Veronica Witte, Arno Villringer, Marco Duering, Stéphanie Debette, Bernard Mazoyer
article
Frontiers in Psychiatry, Frontiers, 2020, 11, ⟨10.3389/fpsyt.2020.00342⟩
identifiant
hal-03003931
titre
Tractostorm: The what, why, and how of tractography dissection reproducibility
auteur
Francois Rheault, Alessandro de Benedictis, Alessandro Daducci, Chiara Maffei, Chantal M. W. Tax, David Romascano, Eduardo Caverzasi, Félix C Morency, Francesco Corrivetti, Franco Pestilli, Gabriel Girard, Guillaume Theaud, Ilyess Zemmoura, Janice Hau, Kelly Glavin, Kessi Jordan, Kristofer Pomiecko, Maxime Chamberland, Muhamed Barakovic, Nil Goyette, Philippe Poulin, Quentin Chenot, Sandip Panesar, Silvio Sarubbo, Laurent Petit, Maxime Descoteaux
article
Human Brain Mapping, Wiley, 2020, 41 (7), pp.1859-1874. ⟨10.1002/hbm.24917⟩
identifiant
hal-03003679