Acute Intermittent Hypoxia in Traumatic Brain Injury

Inclusion Criteria: * Aged 18-65 years * A first time, mild to moderate traumatic brain injury (TBI) confirmed by medical records * When available, a Glasgow Coma Scale score between 9-15 * Able to use a keyboard * Able to understand and communicate in English * Able to consent independently * Able to leave a research visit with a companion/group transportation * Women of child-bearing age must be comfortable confirming a negative pregnancy prior to participating in the study * Not involved in any other research intervention study testing neurobehavioral functioning Exclusion Criteria: * Other neurological diagnoses or a diagnosis of severe psychiatric disorder (e.g., psychosis) or a reported childhood learning disability * Severe aphasia, preventing a participant from understanding the protocol and consent form * Pre-existing hypoxic pulmonary disease * Severe hypertension (\>160/100) * Medically documented history of obstructive lung diseases \[e.g., Chronic obstructive pulmonary disease (COPD) or significant asthma\] * Ischemic cardiac disease * Ineligible to undergo MRI or TMS