The goal of this observational study is to find out if using your brain for a mental task changes how you breathe. Researchers want to compare three groups of adults: people who take opioid pain medicine every day, people with sleep apnea, and healthy people with neither condition. The main questions this study aims to answer are:
* Does breathing change differently during mental tasks in people who take opioids, people with sleep apnea, and healthy controls?
* Is the connection between brain activity and breathing disrupted more in people who use chronic opioids or have OSA, compared with healthy controls, during periods of mental effort?
Researchers will compare the three groups to see if opioid use or sleep apnea makes breathing less steady, or weakens the link between the brain and breathing, when a person is concentrating on a task.
Participants will visit the UC San Diego Sleep Laboratory one time. During the visit, they will:
* Answer questions about sleep, opioid use, and sleep apnea risk.
* Have sensors placed on their skin and scalp to measure brain waves, breathing, and oxygen levels. This is the same kind of equipment used in a regular sleep study, and it does not hurt.
* Sit quietly and rest while their breathing and brain waves are recorded.
* Do a series of short mental tasks on a computer, tablet, or paper, testing things like memory, attention, and thinking speed, while their breathing and brain waves continue to be recorded.
No medicine or treatment will be given during the study, and no blood or other samples will be collected. This study only involves watching and measuring, not testing any treatment.