Brain Injury and Cognitive Function

The objective of this exploratory study is to elucidate the underlying cerebral mechanisms of cognitive deficits. To achieve this, the investigator will apply functional brain imaging techniques to patients suffering from cognitive deficits due to cerebral lesions. The investigator will employ a "single-case" approach, suitable for studying rare behavioral profiles such as acquired reading disorders (alexia) or visual perception impairments (agnosia). If necessary, the investigator will use multiple non-invasive imaging methods in the same patients, including: 1. Magnetic Resonance Imaging (structural and functional), renowned for its spatial resolution and the diverse information it provides, and 2. Electrophysiological methods (MEG and EEG), notable for their temporal resolution. The employed stimuli will consist of visual or auditory presentations of verbal material (words, sentences, numbers, etc.), potentially combined with the collection of simple vocal or motor responses (button presses). The results will be interpreted by integrating the neuropsychological analysis of the deficit and the lesion topography. Importantly, following the methodology of single-case neuropsychology, the stimulation protocols will be modulated and adapted to each individual case. Consequently, parallel data should be collected from healthy control subjects whenever necessary. For protocol development, the investigator will also collect purely behavioral data, without brain imaging, from groups of control subjects.