CIBM Section:

Clinical and Translational Neuroimaging (HUG-UNIGE)

Section Head : Professor Christoph Michel (UNIGE) 

The main research topic of the Clinical and Translational Neuroimaging Section concerns the development and application of electrophysiological brain imaging and non-invasive brain stimulation in humans as well as in animal models to study the dynamics of large-scale neuronal networks. Methodological developments concern high-density EEG source imaging and network synchronization and connectivity measures. Clinical applications focus on neuropsychiatric disorders and lesion-induced network alterations. In cognitive neuroscience, a main focus concerns the functional significance of resting-state activity and the relation to consciousness.

RESEARCH TOPICS

Electrical Neuroimaging

Description: The estimation of the neuronal generators that underlie the scalp potential distribution measured with high-density EEG requires sophisticated head models based on individual MRI and source models that incorporate the properties of the generation and propagation of the electric field. The laboratory develops these models and implement them in the academic software CARTOOL developed by Denis Brunet.

Investigators: Christoph Michel (UNIGE), Denis Brunet (UNIGE)

Collaborator: Martin Seeber

EEG microstates

Description: Brain activity at rest is not random but highly organized in large-scale networks that synchronize for sub-second time periods. EEG microstates allow to characterize these network patterns and study their temporal dynamics. EEG microstates are considered as “atoms of thought”, whose syntax, i.e. the evolution in time determine the content of the thoughts. The laboratory studies these EEG microstates and tries to decipher the rules that underlie the EEG microstate dynamics. 

Investigators: Christoph Michel (UNIGE), Denis Brunet (UNIGE)

Collaborators: Martin Seeber, Fiorenzo Artoni, Nicolas Roehri

Neuropsychiatric Diseases

Description:

An important line of research concerns the search for EEG biomarkers of different neuropsychiatric diseases. In collaboration with psychiatrists in the framework of the NCCR Synapsy, the lab is studying EEG microstates as well event-related potentials in different cohorts of patients with psychiatric diseases including psychosis, mood disorder, ADHD, autism and eating disorders, in order to define EEG-based biomarkers of these diseases.

Investigators: Christoph Michel (UNIGE), Cristina Berchio, Vincent Rochas

Collaborators: Stephan Eliez, Marie Schaer Jean-Michel Aubry, Alexandre Dayer

Neurofeedback

Description: EEG-based neurofeedback is a powerful tool to alter ongoing brain dynamics and modulate the state of the brain. While traditionally EEG neurofeedback is based on controlling oscillations in certain frequencies, we are developing neurofeedback methods based on spatial features of high-density EEG (EEG microstates as well as EEG source dynamics) with the hypothesis that such features more directly allow to modulate large-scale network activity.

Investigators: Tomas Ros (UNIGE), Christoph Michel (UNIGE)

Collaborators: Perroud Nader, Alexandre Dayer

Memory and cognition

Description: Memory loss in elderly is of increasing clinical importance given the increasing life expectancy. We are studying the EEG correlates of memory retrieval, in particular autobiographic memory using high-density EEG and fMRI. We are particularly interested in developing methods that allow to preserve memory loss in mild cognitive impairment and Alzheimer disease. A promising method currently explored is transcranial alternate current stimulation (tACS).

Investigators: Lucie Brechet (UNIGE), Christoph Michel (UNIGE)

Collaborator: Alvaro Pascual-Leone (Harvard Medical School)

Altered states of consciousness

Description: Consciousness is altered in different states of the healthy brain (e.g. sleep) and in different neuropsychiatric diseases. We are interested in the EEG signatures, particularly EEG microstates, that characterize altered states of consciousness.

Investigators: Lucie Brechet (UNIGE), Christoph Michel (UNIGE)

Collaborator: Giulio Tononi (Wisconsin University)

Pre-surgical planning

Description: Intracranial surgery requires a detailed individual presurgical and intraoperative mapping of brain functions to minimize the risk of postsurgical neurological deficits and decline of quality of life. Most attention is put on brain regions controlling speech and motor functions. However, higher cognitive functions responsible for social functioning, personality, and the sense of self may also be affected by brain surgery. Such brain regions are not well understood, making the assessment of surgical risks difficult. Using high-density EEG we study the brain mechanisms of the bodily and cognitive self in healthy participants and in patients undergoing resection of brain tumors or epileptic foci.

Investigator: Christoph Michel (UNIGE)

Collaborators: Karl Schaller, Olaf Blanke

Animal electrophysiology

Description: In an attempt to better understand the basic neurophysiological mechanisms underlying large-scale brain networks measured with EEG, we have installed an animal electrophysiology lab aiming at recording high-density scalp EEG in rodents comparable to the human recordings. This facility allows us to study the mechanisms that lead to the development and maintenance of physiological as well as pathological whole-brain networks by adding intracranial multi- and single unit recordings as well as other imaging- and stimulation methods to the scalp EEG.

Investigators: Charles Quairiaux, Christoph Michel (UNIGE)

Collaborator: Karl Schaller