The main objectives of the study are to assess (1) patterns of brain activity/connectivity that confers greater cardio-autonomic/emotion regulation, (e.g., heart rate variability, blood pressure reactivity, inflammatory-immune activation, etc.), during rest, mental stress, and anger-related distress, (2) whether changes in breathing pace mitigate task-based effects on cardio-autonomic-immune regulation, and (3) whether these patterns vary as a function of HIV or pre-hypertensive (HTN) status-related changes to the brain structures underlying cardioautonomic and emotion regulation.