Medical Cannabis and Behavior

Inclusion Criteria: * Medical cannabis users (n=120) will be required to 1. Be ages 30-75; 2. Be qualified for a medical cannabis prescription based only on a diagnosis of chronic pain; note that individuals can, in theory, utilize medical cannabis for more than one qualifying condition. People with orthopedic pain will be prioritized. 3. Have normal or corrected-to-normal vision and hearing; 4. Be free of current and past DSM-V-defined substance use disorders; have \< 5 lifetime recreational uses of illicit drugs. 5. Have limited daily exposure to nicotine (e.g., no daily smokers/vapers; use of nicotine products fewer than 5 occasions weekly); 6. Willing to abstain from alcohol, nicotine, and other (non-treatment) drugs for 24 hours prior to study. Abstinence will be verified by breathalyzer and urine drug screening; must not test positive on breathalyzer and urine drug screenings for any nonprescribed psychoactive substance or for cannabis (at baseline); 7. Must be right handed as assessed by the Edinburgh Handedness Inventory; 8. No history of daily cannabis use; limited cannabis product use (recreational or therapeutic) within the past three months; 9. Able to schedule and complete a multi-hour single session protocol; 10. Have sufficient manual mobility to be able to complete computerized neurocognitive assessments; 11. Able to communicate with the researchers by phone during the four month pre-post assessment interval Pain patients who are not using medical cannabis (n=60) will be required to: 1. Be ages 30-75; 2. Suffer from a chronic pain condition that could qualify them for medical cannabis; People with orthopedic pain will be prioritized. 3. Have normal or corrected-to-normal vision and hearing; 4. Be free of current and past DSM-V-defined substance use disorders; have \< 5 lifetime recreational uses of illicit drugs. 5. Have limited daily exposure to nicotine (e.g., no daily smokers/vapers; use of nicotine products fewer than 5 occasions weekly); 6. Willing to abstain from alcohol, nicotine, and other (non-treatment) drugs for 24 hours prior to study. Abstinence will be verified by breathalyzer and urine drug screening; must not test positive on breathalyzer and urine drug screenings for any non- prescribed psychoactive substance or for cannabis (at baseline); 7. Must be right handed as assessed by the Edinburgh Handedness Inventory; 8. No history of daily cannabis use; cannabis use within the past three months limited to a few times. 9. Able to schedule and complete a multi-hour single session protocol; 10. Have sufficient manual mobility to be able to complete computerized neurocognitive assessments; 11. Able to communicate with the researchers by phone during the four month pre-post assessment interval Within both groups, concomitant opioid use will be allowed as will other prescribed treatments. Controls will be matched to the cannabis group on age, sex, socioeconomic status (SES), type of pain condition (orthopedic pain will be targeted) and comorbid opioid use. All potential participants must indicate at the baseline enrollment that they have no immediate plans to relocate from the Twin Cities metro area (e.g., must be willing and able to participate in longitudinal assessment for a four-month period). Exclusion Criteria: 1. Cannot have a degenerative neurological condition or a neurological condition that impacts brain function (e.g., epilepsy); 2. No contraindications to MRI scanning; 3. No lifetime history of severe DSM-V psychopathology (psychotic disorders, bipolar disorder); if currently treated mood for anxiety disorders, must be stable; 4. No current pregnancy or pregnancy within the prior 3 months; cannot be lactating;