Interests

  Neurophysiological oscillatory and dynamical mechanisms regulating cortical arousal related to vigilance and human cognition in healthy subjects with normal cognitive-motor performances, and investigation of the species-specific features of those mechanisms using primate gray lemurs and mice as control speciesOur studies aim at understanding neurophysiological oscillatory and dynamical mechanisms regulating cortical arousal in the cerebral cortex during states of low or moderate vigilance as well as sensory (somatosensory painful and non-painful, visual, and auditory) and cognitive-motor information processing as revealed by the analysis of electroencephalographic (EEG) activity in healthy humans with normal cognitive-motor performances.  In the study of the neurophysiological oscillatory mechanisms, the main focus is on the role of alpha rhythms in the modulation of global cortical excitation and inhibition to maintain the low vigilance over sleep intrusion in the resting state condition and support attention, perception, and memory episodic information processes.  In other studies in gray lemurs and mice (control species), we demonstrated that alpha rhythms  play this role in primates but not in mice.Neurophysiological oscillatory and dynamical mechanisms regulating cortical arousal related to vigilance and human cognition in healthy subjects with high cognitive-motor performances (elite athletes and professional musicians)Our studies aim at understanding neurophysiological oscillatory and dynamical mechanisms regulating cortical arousal in the cerebral cortex during states of low or moderate vigilance as well as sensory (visual, and auditory) and cognitive-motor information processing as revealed by the analysis of electroencephalographic (EEG) activity in healthy humans with high cognitive-motor performances such as elite athletes and professional musicians.  In the study of the neurophysiological oscillatory mechanisms, the main focus is on the role of alpha rhythms in the modulation of global cortical excitation and inhibition according to the concept of “neural efficiency” defined as the ability of those mechanisms to maintain a low level of excitability in the cortical regions irrelevant for the cognitive-motor task demands or for maintaining the low vigilance over sleep intrusion in the resting state condition.  We repeatedly confirmed this hypothesis in most of the different experimental conditions and athletes.Abnormal neurophysiological oscillatory and dynamical mechanisms regulating cortical arousal related to vigilance and human cognition in patients with cognitive deficits due to different physiopathological processes, and investigation of the species-specific features of those abnormal mechanisms using mice as control speciesOur studies aim at understanding how pathological alterations in certain neuromodulatory ascending activating systems (i.e., cholinergic and dopaminergic in Alzheimer’s, Parkinson’s, and Lewy Bodies diseases) or white matter neuro-communication systems (i.e., HIV, Stroke, Multiple Sclerosis, and Obesity) can affect as a “natural experiment” neurophysiological oscillatory mechanisms regulating cortical arousal in the cerebral cortex during states of low or moderate vigilance or cognitive processes as revealed by the analysis of electroencephalographic (EEG) activity in patients with the mentioned brain-body diseases. The main hypothesis is that abnormalities in those neurophysiological oscillatory and dynamical mechanisms are responsible for a part of cognitive deficits measured in the relative patients by neuropsychological tests. In other studies in mouse models of Alzheimer’s disease with mutations of APP and PS1, we demonstrated that abnormalities in alpha rhythms play this role in patients but not in mice. In mice the abnormalities of neurophysiological oscillatory mechanisms are observed in lower frequency bands such as delta and theta, thus confirming the specific functional architecture of those rhythms in patients