The purpose of this study is to determine whether obstructive sleep apnea affects sleep dependent memory and learning. Subjects with apnea will be given a test of perceptual skill learning (the Visual Discrimination Task (VDT)) that has previously been shown to depend on sleep. Subjects will be tested on this task before and after sleep. The difference in performance after sleep compared to before sleep provides a measure of sleep dependent learning. Participants will be tested on one night when they have less apnea because they are using continuous positive airway pressure (CPAP) as prescribed by their physician, which is well known to reduce apnea; and on another night when they are in their native state and have a greater degree of apnea. Memory performance will be compared between the two nights to determine how apnea affects sleep dependent memory.

Inclusion Criteria:

• Clinical diagnosis of sleep apnea
• Use PAP therapy as prescribed by his/her physician for 3-4 weeks prior to enrollment
• Right-handed

Exclusion Criteria:

• Major neurological or psychiatric condition
• Chronic pain condition
• Learning disabilities
• Serious brain or head injury (e.g. seizure, stroke, head trauma)
• Major surgery or general anesthesia in the past year
• Pregnant or nursing
• Problems with eyes or vision (besides corrected-to-normal with glasses or contacts)
• Past diagnosis of infection that can affect the brain (e.g. meningitis, HIV/AIDS)
• Medications that affect sleep (antidepressants, muscle relaxants, sleep aids, beta-blockers, stimulants, or corticosteroids)
• Recreational drug use, including marijuana
• Night-shift work
• Cancer or cancer treatment in the last 2 years
• Smoke more than 10 cigarettes per day
• Consume more than 3 caffeinated foods or beverages per day