Inclusion Criteria:  Diagnosis of VS or MCS based on the CRS-R .  Chronic status:  3 months post-injury for non-traumatic etiologies 12 months post-injury for traumatic etiology 18 years of age or older. If on a psychotropic medication regimen, that regimen will be stable for at least 4 weeks prior to entry to the study and the patient will be willing to remain on a stable regimen during the protocol.  Exclusion Criteria:  History of neurological disorder (other than the brain injury). Unsuitability to undergo Magnetic Resonance (MR) assessment (e.g., non-MR compatible implants). Unsuitability to undergo LIFUP neuromodulation (e.g., presence of non-bone implant or absence of bone under the expected positioning of the device by the left temporal bone window). Manifest continuous spontaneous movement (which would prevent imaging) Participation in another concurrent clinical trial. Having undergone PET, CT, or other exam involving the use of ionizing radiation in the 12 months prior to the date of scheduled admission to Casa Colina. Dependence on ventilator.