Brain Connectivity and Perceptive Surfaces in Chronic Low Back Pain (SUPER-RMNf)

Rationale: Chronic Low Back Pain (CLBP) is often associated with "cortical reorganization," where the brain's map of the back becomes less precise. This phenomenon contributes to the persistence of pain and reduced body awareness. While traditional rehabilitation focuses on the physical structure of the spine, neurocognitive approaches use "perceptive surfaces" to provide specific tactile and proprioceptive feedback, aiming to "retrain" the brain's representation of the trunk. Objective and Hypothesis: The primary goal of this study is to investigate how the brain responds to stimulation from these perceptive surfaces in patients with CLBP compared to healthy individuals. The investigators hypothesize that using these surfaces will lead to immediate changes in functional brain connectivity, particularly in areas responsible for body awareness and pain processing (somatosensory and salience networks). Study Procedures: The study will involve 20 patients with chronic non-specific low back pain and 20 healthy volunteers. All participants will undergo a Functional Magnetic Resonance Imaging (fMRI) session. During the scan, participants will be placed on a specialized perceptive surface. Brain activity and connectivity will be measured at rest and during specific tactile stimulation. Additionally, advanced imaging techniques (SANDI model) will be used to look at the microscopic structure of brain cells (neurons). Clinical Impact: By comparing the two groups, the study aims to identify specific "brain signatures" of recovery. This could help clinical professionals understand if perceptive surfaces can effectively restore cortical maps, leading to better personalized rehabilitation strategies for chronic pain.

Inclusion Criteria: * Aged between 18 and 45 years * Right-handed dominance * Good general health condition * Ability to provide written informed consent. For the patient group: \- Clinical diagnosis of non-specific chronic low back pain with a duration of more than 3 months For the control group: \- Healthy volunteers without a history of chronic pain Exclusion Criteria: * Contraindications to 3T Magnetic Resonance Imaging, such as pacemakers or non-compatible metallic implants * Pregnancy or breastfeeding * Presence of significant neurological or psychiatric pathologies * Current use of psychoactive medications. * Sensory or motor disorders of the lower limbs that prevent interaction with the perceptive surface. * Unstable or acute clinical conditions. * Inability to remain still during the MRI scanning procedure