Acute Effects of Cannabis on Cognition and Mobility in Older HIV-infected and HIV-Un-infected Women

7% delta9-THC cigarettes will be smoked by 'light the cigarette' (30 sec), 'get ready' (5 sec), 'inhale' (5 sec), 'hold smoke in lungs' (10 sec) and 'exhale.' Participants will smoke 3 puffs in this manner, with a 40-sec interval between each puff.

0% THC cigarettes will be administered to HIV negative women. Participants will be instructed to 'light the cigarette' (30 sec), 'get ready' (5 sec), 'inhale' (5 sec), 'hold smoke in lungs' (10 sec) and 'exhale.' Participants will smoke 3 puffs in this manner, with a 40-sec interval between each puff.