Anne Giersch

Biography

Anne Giersch studied medicine, specialized in psychiatry and was trained in research. She is a research director at the French National Institute of Health and Medical Research (Inserm) and heads the Psychiatry team of the Strasbourg Translational Neuroscience & Psychiatry Unit (STEP).

After completing a master's degree in neuroscience in parallel with her medical studies, she completed a PhD in Strasbourg, followed by a post-doctorate in Tübingen (Germany), which trained her in psychophysics - the mysteries of visual perception - and psychopharmacology. She was recruited as an Inserm researcher in Strasbourg in 1998.

In the course of her studies on visual perception in schizophrenia, and her work with Yvonne Delevoye-Turrell on motor action, she became interested in how perception is timed in patients. For just over 15 years, Dr. Giersch has been exploring the question of the continuity of time, linked to that of the sense of self. Her hypothesis is that an excessive sensitivity to small asynchronies disrupts the passage of time in patients.

While reflecting on the sources of asynchrony in everyday life, and thanks to a suggestion from Pierre Marquet, she started researching the vestibular system. She discovered Christophe Lopez's work on sense-of-self disorders in vestibular syndromes, and engaged with Professor Anne Charpiot and her service for vestibular disorders at the Strasbourg University Hospitals.

Fellowship 2024

Dates - 01/10/2024-30/09/2026

Project summary

BODILY SELF DISORDERS: ROLE OF THE VESTIBULAR SYSTEM, AND INTERPLAY WITH VOLUNTARY ACTION AND TIMING

The bodily sense of self is both an evidence and a mystery. It is obvious that we have only one body, despite multiple sources of bodily information – amongst which sense of touch, body position, cardiac and intestinal. How this multiple information is attributed to a single source, and why the bodily sense of self is sometimes disturbed, remains a mystery. The multiplicity of sources of information means that the sense of bodily self may differ between individuals, particularly in the case of a pathology, but also that it is difficult to measure: which source of bodily information should be explored? How can we measure a sense that is difficult to describe verbally?

Some patients with disorders of the bodily sense of self describe difficulties in moving around. The project explores the distinction between self-related movement and true movement of the environment: every time we move, information from the environment is mirrored on our retina, and we have to distinguish this (self-related) movement from the movement of objects in the environment. This situation amounts to making a distinction between self and non-self, and a disruption of this distinction can blur the sense of self. Several mechanisms are involved, and objective of the project is to distinguish between the role of vestibular information, motion perception, and the mechanisms mobilized in the case of voluntary movement. To highlight inter-individual differences, several pathologies will be explored: schizophrenia, vestibular syndrome and borderline personality disorders. Disturbances of the bodily sense of self can indeed be observed in all these pathologies. The approach of the project is based on experimental psychology methods, and body movement measurement and induction techniques. Virtual reality will be used to understand how self-related movements are distinguished from real movements in a dynamic environment. Experimental manipulations and their effect on the people taking part in the study will help to understand how different mechanisms interact and participate in the bodily sense of self. They will also lead to a better understanding of the causes of disorders of the sense of self, thus opening up new therapeutic perspectives.