Thesis defence : Sonja BANJAC

Current theoretical frameworks suggest that human behaviors are based on strong and complex interactions between cognitive processes such as those underlying language and declarative memory that are supported by the interaction between underlying cortical networks. Patients with temporal lobe epilepsy (TLE) present a model for studying the interaction between language and memory since they frequently show difficulties in both domains. The aim of this thesis was twofold. On one side, it aimed at describing language-memory interaction from the fundamental cognitive neuroscience perspective. On the other, it focused on the clinical application of this interactive perspective.In the present work, we first demonstrate how language and memory can be mapped interactively using a novel fMRI protocol. Using this protocol in healthy individuals, we show that this interaction is based on an extensive fronto-temporo-parietal language and memory network (LMN) including subcortical structures that corresponds well with the network which could be expected based on the existing models. We subsequently explored the reorganization of LMN in left TLE patients using the same protocol. Our results indicated that these patients employ similar LMN, but demonstrate widespread inter- and intra-hemispheric reorganization. They showed reduced activity of regions engaged in the integration and the coordination of the LMN.Following these results, we explored the functional dynamics of this interactive network. We showed that LMN is dynamic and reconfigures according to task demands and neurological status. By exploring the differences between state-dependent LMN configurations, we identified the key language and declarative memory subprocesses the network is trying to support with its adaptation. On the other hand, studying the reorganization of this reconfiguration in TLE patients allowed us to understand the supplementary processes language-memory interaction needs when the standard interface is not functional.We conclude our work by proposing a neurocognitive model of language-memory interaction based on the integration of our findings. Moreover, we discuss the importance of exploring this interaction within presurgical evaluation for TLE patients, especially individually. In addition, we present as perspectives of this work the multimodal prediction of postsurgical cognitive outcome in TLE patients. Our work supports the perspective that complex and interactive cognitive functions, such as language and declarative memory, should be investigated dynamically, considering the interaction between cognitive and cortical networks.

Encadrante :
- Directeur de thèse : Monica BACIU - 0476825880 - Monica.Baciuuniv-grenoble-alpes.fr (Monica[dot]Baciu[at]univ-grenoble-alpes[dot]fr) -

Keywords: epilepsy, language, memory, functional MRI, connectivity,

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