Disorders of the Sense of Self and Physical Activity

Schizophrenia (SZ) patients with metabolic syndrome, patients with vestibular syndrome, and patients with borderline personality disorder, would benefit from physical activity (PA). Yet patient adherence to PA is low, at least in the case of SZ. the investigators work and the literature lead the investigators to consider that, in addition to motivational aspects, disorders of the bodily sense of self could play a role in this lack of adherence. Simply walking involves visual movements related to the self, which must be distinguished from movements in the environment. This means a distinction between self and not-self. Furthermore, these movements are all the more difficult to distinguish as they may also result from the fact that hidden objects become visible as a result of our own movement. In all sense-of-self disorders can themselves affect physical training, and the investigators will measure them in the first stage. In the second stage, the investigators will apply a standard, risk-free PA protocol by walking (3x3 sessions of 30 min). the investigators will test the impact of physical training on the sense of self under different conditions, with one environment minimizing self-related movement, vs. 2 environments with a variable level of enrichment (i.e. hidden objects inducing more or less self-related movement).

At the end of the protocol, the investigators will offer participants who wish to take part in an ancillary study, i.e. a walking session with mixed-reality goggles. These will superimpose a luminous flux on the periphery of the visual field. According to results obtained in the laboratory, this flux could restore sensory mechanisms impaired in schizophrenia. the investigators will use these glasses in the most difficult condition for the patient, and verify their impact.