Lipid restriction is significant in anorexia nervosa and limits therapeutic management. The multisensory perception of fat is altered, creating an aversion to lipids. The investigators aim to characterize the impact of sensory stimulation (smells or images) associated with specific tastes using neuropsychological assessments and functional MRI. Some volatile aromas can enhance the perception of the associated taste. The investigators hypothesize that such associations are altered in anorexia nervosa for fatty foods but may be preserved for sweet tastes, and that this alteration contributes to the maintenance of the disease. The interdependence of different sensory perceptions of lipids could play a major role in the therapeutic approach, aiding in the deconditioning of this aversion and the restoration of positive food sensory associations.

Inclusion Criteria:

• Person affiliated or entitled to a social security scheme
• Person having received informed information on the study and having co-signed, with the investigator, a consent to participate in the study
• female person
• Person affiliated or entitled to a social security scheme
• Over 18 years'old
• Knowing how to read and write French
• Patient diagnosed with anorexia nervosa according to DSM-5 criteria for at least 5 years (HAS criteria). Failure of prior outpatient or/and hospitalization care over the last 12 months: stable or falling low BMI, unmodified food restriction, continued fear of weight gain, disturbances in the perception of body image
• BMI < 18.5 kg/m² for volunteers in a state of constitutional thinness. The absence of eating disorder and the absence of restriction to DEBQ questionnaires. Fertility preserved.
• For volunteers of normal weight: 18.5 kg/m² < BMI < 25 kg/m²

Exclusion Criteria:

• Pregnant women, parturient, nursing mothers;
• Persons deprived of their liberty, hospitalized without consent, hospitalized for purposes other than research;
• Minors
• Refusal of the study by the participant
• Person incapable of giving informed consent
• Artificial nutrition
• Associated organic damage favoring undernutrition: other chronic diseases (digestive, infectious, endocrine, pulmonary, cardiac, neurological), neoplasms, etc.
• Abuse of psychoactive substances except tobacco
• Characterized depressive episode, psychosis
• Score less than 14 on the Edinburgh laterality questionnaire.
• Contraindications to MRI or allergy to one of the components of the olfactory and taste tests
• Smokers
• Smell or taste alterations