Inclusion criteria:  Absence of clinical symptoms of impaired hypoglossal nerve and cortico-lingual pathways; Absence of history of surgical interventions in the tongue area; The subject has read the information sheet and signed the informed consent.  Exclusion Criteria:  Clinical symptoms of hypoglossal nerve or cortico-lingual pathway (dysarthria, dysphagia (pseudobulbar palsy) lesions, flaccid paralysis of the tongue muscles, atrophy and fasciculations of the tongue muscles); Tumors, metastatic lesions and cysts in the region of the brain stem, posterior cranial fossa, base of the skull, in the region of the carotid segment, salivary glands; Vascular pathologies in the carotid sinus area: vascular malformations, dissection of the internal carotid artery aneurysm, venous thrombosis; Recent dental procedures with one of the following complications: development of an abscess, direct injury to the nerve by medical equipment, development of hematoma; History of carotid endarterectomy; Motor neuron disease and other neurodegenerative or demyelinating diseases; History of cancer and courses of radiation therapy; The presence of implantable programmable devices.