Thesis defense Roselyne Chauvin (Donders series 410)

Cognitive functions interact by exchanging information across complex and distributed networks of brain areas. During task performance, specific networks modulate their activity in order to process input information and to produce appropriate output. This thesis is about the functional organization of the brain during cognitive performance and addresses network commonalities and specificities between cognitive tasks. Using functional magnetic resonance imaging, this thesis describes a new framework for the examination of changes in communication between brain areas compared to the state of their baseline activity. This enables a direct comparison between tasks, offers a new viewpoint on brain function, and integrates knowledge across different cognitive domains.

The validation of the utility of this new perspective and method covers the understanding of modulation of the functional connectivity under different state of mind such as tiredness, attention fluctuation or change in mood and also addresses changes in efficiency of this modulation during normal and abnormal development. In normal development, changes in modulation characterize maturation mechanisms coherent with skills improvement in working memory, reward processing and inhibition-attention systems. In abnormal development, here attention deficit and hyperactivity disorder and autism spectrum disorder, the method addresses how alterations in this functional organization can be linked to multiple current theories.
This thesis ends with a discussion on the benefits and possible applications of this new method and new knowledge that results from this new approach to the organization of the brain.