There is provided an apparatus, a method and a computer program. The apparatus comprises measuring means (100) for generating a group of voxel values of a patient (32), a voxel value representing an electromagnetically detectable functional state in a brain voxel of the patient (32), detecting means (110) for generating from the group of voxel values of the patient (32) an indication that represents a level of a specific medical disorder of the patient (32), and illumination means (35, 40, 120) for directing non-invasively a dose of light to the brain of the patient (32).
