Research

The best-known memory disorders are those affecting episodic memory. They consist of forgetting events as they happen. There is another, rarer pathology, in which patients progressively lose their knowledge of the world. We have helped to demonstrate that there are two distinct clinical entities (loss of verbal labels, or 'deep' semantics). This has repercussions not only on treatment, but also on the support provided by family and friends.
 
Financement : Bourse doctorale EDISCE
Chercheurs : Olivier Moreaud, Mathilde Sauvée, Annik Charnallet, Céline Souchay, Méline Devaluez, Stéphane Rousset

• Read more about Pathology of Semantic Memory

Metacognition, or the ability to evaluate our performance, has been studied extensively in the fields of memory (see above) and visual perception, but much less in other areas such as motor skills. This interdisciplinary thesis project (co-supervised by Céline Souchay, Aïna Chalabaev and Estelle Palluel) therefore aims to explore our self-evaluation capacities in motor tasks. The aim will be to conduct studies that are both 'systematic', i.e. carried out under controlled laboratory conditions, and 'representative', i.e. more ecological.
We will also explore motor metacognition in children and in the context of developmental coordination disorders (dyspraxia).

Financements : CBH Graduate School
Chercheurs : Céline Souchay, Lise Brun

• Read more about Metacognition and motor skills

We seek to identify the electrophysiological mechanisms that give rise to the phenomenal experience associated with the processing of perceptual information, in other words what it feels like to consciously perceive an object. We also study the brain's ability to observe itself, which gives us the so-called metacognitive ability to evaluate and control our own mental states. Our hypothesis is that consciousness and metacognition depend on a mechanism of accumulation of evidence.

• Read more about Axis 4. Perceptual awareness and metacognition

We are developing a neurobiological model of visual recognition. This model is predictive, that is to say it is based on the hypothesis that our brain interprets the external world according to a pre-existing model that it continually updates according to the information, particularly visual and emotional, that it receives. We draw inspiration from this model to produce more efficient artificial intelligence (neural networks).

• Read more about Axis 3. Proactive vision and emotional experience

We study the role of eye movements in perceptual, motor, or cognitive processes using experimental psychology paradigms with controlled but nevertheless ecological stimuli (such as faces and visual scenes). We also use these eye-tracking measurements as biomarkers of cognitive disorders in various ophthalmological pathologies (AMD, glaucoma), neurodegenerative (Parkinson's, Alzheimer's) and psychiatric (bipolar disorders)

• Read more about Axis 2. Active vision and eye movements

We are developing models of visual perception inspired by the biology of retinal neurons. For example, we propose a model of color perception inspired by the mosaic of retinal cones and their non-linear and adaptive processing. Our algorithms significantly improve the color processing of digital images. We therefore apply our models to digital cameras and machine vision systems.

• Read more about Axis 1. Visual sensory inputs

Monica BACIU

Marcela PERRONE-BERTOLOTTI

Christine BULTEAU

Doctorante: Anna BORNE



Rasmussen encephalitis is a chronic autoimmune disease characterized by progressive unilateral hemispheric atrophy. This pathology causes drug-resistant partial epilepsy and is accompanied by progressive, disabling neurocognitive disorders. Due to its drug resistance, the only curative treatment is hemispherotomy, a functional disconnection between the hemispheres. Given the young age of surgery, patients with Rasmussen are expected to benefit from significant brain reorganization that allows significant recovery of cognitive functions, even if it occurs unevenly, depending on the specific developmental trajectories of these functions. and individual cognitive and cerebral reserve. In addition to the cognitive recovery observed in adulthood, different models of brain reorganization have also been described. Therefore, it is of particular interest to understand the strategies recruited by these patients due to neuroplasticity. Overall, this research project aims to evaluate both the cognitive outcome and the reorganization of brain networks in adult patients with Rasmussen encephalitis after hemispherotomy performed during childhood. A multimodal approach will be used, combining experimental psychology and neuropsychology to assess a wide range of cognitive functions (language, executive functions, theory of mind and memory) and clinical scores, as well as fMRI in resting state and DTI-MRI to measure the connectivity of functional and structural networks of the functional hemisphere, respectively. The originality of this work also consists of the development of a new multi-cognitive battery specifically adapted to this population (LEXTOMM, Perrone-Bertolotti, M., 2021). We thus wish to improve our understanding of patients with Rasmussen encephalitis by describing cognitive and cerebral phenotypes, with new directions for cognitive rehabilitation and pre-habilitation to ensure their best possible recovery.

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Monica BACIU

Mathilde SAUVEE

Olivier MOREAUD

The incidence of cognitive neurodegenerative diseases (CND) increases with age. Alzheimer's disease (AD) is the most common. Other diseases related to Alzheimer's disease (AD) share common features with AD, but vary in terms of genetics, clinical course, neuropsychology, proteinopathy, neuroimaging, evolution and management. A major advance is the use of biomarkers in CSF to approach neuropathological diagnosis. Artificial intelligence (AI) methods applied to multimodal parameters have real phenotyping potential (i.e. automatically identifying multimodal characteristics specific to a pathology, enabling it to be distinguished from others). In addition, the development of AI-based clinical decision support atlases is booming. We have a retrospective database with prospective potential that will enable us to carry out this project.

An example is provided in the image above.

CN= cognitive normal; sMCI= Stable mild cognitive impairment; pMCI= Progressive MCI; AD= Alzheimer's disease; FTLD: Frontotemporal Lobar Degeneration.

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Modèle L∪M langage-union-mémoire (Roger et al., 2022)

See the publications in the HAL-ANR portal

• Read more about ANR REORG