Cannabis Observations on Brain Waves, Retrieval, and Attention: Experiment 4

1. Must be between the ages of 21 and 40 and provide informed consent; 2. Must be right-handed (Laterality Quotient \> 60 on Edinburgh Handedness Inventory - Short Form136); 3. Heavy users (HU) in Experiments 1, 2, 3, and 4: 1. Must use cannabis at least 4 days during the month; 2. Must be a cannabis user for at least a year; 4. Non-users (NU) in Experiment 2: 1. Must not have used cannabis for prior 6 months; 2. Must have at least one episode of lifetime cannabis use; 5. Must self-report not using other illicit recreational drugs (e.g., cocaine, benzodiazepines (non-prescription), opiates (non-prescription), MDMA, sedatives, or methamphetamine) in the past 30 days, during the Pre-Screening; 6. Must not test positive on a urine toxicology test for drugs of abuse at the Baseline Appointment (TDS); 7. Must not be using psychotropic medications, however anti-depressant, non-benzodiazepine anti-anxiety, and ADHD medications are ok. ADHD medication users must be willing to abstain from ADHD medication use on appointment days; ADHD medications, even extended-release forms, are short acting and medication" holidays" (e.g., on weekends and holidays) are routine in individuals prescribed ADHD medications, without adverse effects. 8. Must not be a regular nicotine user (≤4 days per week; cigarette, E-cigs, or smokeless); 9. Must not have used caffeine or nicotine (cigarette, E-cigs, or smokeless) for 4 hours; 10. Must have a breath alcohol level of 0 at screening (to sign consent form); 11. Must not be actively seeking or in treatment for any substance use disorder (drug use levels will be carefully monitored via Timeline Follow Back (TLFB) throughout the study to assess any confounding influences of drug or alcohol use; 12. Female subjects must not be or trying to become pregnant (as indicated by a pregnancy test \& screening form administered at Baseline); 13. Must not be in treatment for psychotic disorder or bipolar disorder; or have a history with these disorders; 14. Must not have any physical characteristics (e.g., thick hair, head size exceeding the limit of the net, dyed hair) or experience any technical difficulties during testing that result in a poor-quality EEG recording. 15. Participants in Experiment 4 a. Must not have participated in Experiment 3