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

NCT07679581 | Recruiting

• 2 other identifiers: 20-0309: Experiment 4R01DA052431
• Study Type: observational
• Target: 64
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigates the impact of ∆9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on recognition memory in healthy, regular cannabis users. Participants complete the same recognition memory task after self-administering one of two different strains of cannabis flower one day and while not intoxicated another day. Event-related potentials (ERPs) are measured via electroencephalogram (EEG) during the recognition memory task. Blood is collected to quantify THC and CBD exposure. Participants also complete self-report measures of medical history, sleep quality, subjective cognitive function, physical activity, psychological functioning, substance use, and acute drug effects.

Conditions

Cannabis; Memory; Electroencephalography

Keywords

Cannabis; Memory; Electroencephalography

Outcome Measures

Primary Outcomes (4)

• Difference in ERP amplitude (FN400)

  The FN400 event-related potential (ERP) old/new effect will be measured using electroencephalography (EEG) during a recognition memory test. The FN400 reflects familiarity-based memory retrieval and is defined as the mean ERP amplitude difference between correctly recognized previously presented items ("hits") and correctly rejected novel items ("correct rejections") at mid-frontal electrode sites during the 300-500ms post-stimulus interval.

  Intoxicated session and not-intoxicated session (about 1 week)

• Difference in ERP amplitude (parietal)

  The parietal ERP old/new effect will be measured using EEG during a recognition memory test. The parietal old/new effect reflects recollection-based memory retrieval and is defined as the mean ERP amplitude difference between hits and correct rejections at parietal electrode sites during the 500-800ms post-stimulus interval.

  Intoxicated session and not-intoxicated session (about 1 week)

• Difference in retrieval memory accuracy

  Behavioral accuracy during recognition memory test will be assessed by the number of hits and correct rejections made during memory recall. Retrieval memory accuracy will be compared between intoxicated and not-intoxicated sessions.

  Intoxicated session and not-intoxicated session (about 1 week)

• Difference in retrieval memory performance

  Memory performance will be assessed via reaction time, measured by a photocell during recognition memory testing and concurrent EEG. During the recall phase, a light indicator will appear in the bottom-right corner of the stimulus screen when a prompted image is presented, activating the photocell. This indicator disappears once the participant responds. The interval between stimulus onset and the participant's "new" or "old" response is used as the reaction time measure for both intoxicated and non-intoxicated sessions. Retrieval memory performance will be compared between intoxicated and not-intoxicated sessions.

  Intoxicated session and not-intoxicated session (about 1 week)

Secondary Outcomes (8)

• Change in Positive and Negative Affect Schedule (PANAS)

  During a single non-intoxicated laboratory session and immediately before and immediately after acute cannabis use during a single intoxicated laboratory session

• Change in Drug Effects Questionnaire (DEQ)

  During a single non-intoxicated laboratory session and immediately before and immediately after acute cannabis use during a single intoxicated laboratory session

• Change in Addiction Research Center Inventory (ARCI-M)

  During a single non-intoxicated laboratory session and immediately before and immediately after acute cannabis use during a single intoxicated laboratory session

• Change in Marijuana Craving Questionnaire (MCQ)

  During a single non-intoxicated laboratory session and immediately before and immediately after acute cannabis use during a single intoxicated laboratory session

• Change in Profile of Mood States (POMS)

  During a single non-intoxicated laboratory session and immediately before and immediately after acute cannabis use during a single intoxicated laboratory session

Other Outcomes (4)

• Exploratory: Correlations between genes related to cannabinoid metabolism, cannabis-related behavior, and neurocognitive function with ERPs and recognition memory performance

  Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)

• Exploratory: Moderation of primary effects by baseline sleep quality using the Patient-Reported Outcomes Measurement Information Systems (PROMIS)

  Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)

• Exploratory: Moderation of primary effects by baseline affective symptoms using the Depression Anxiety Stress Scale (DASS)

  Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)

Interventions

Cannabis (smoked flower) DRUG

Self directed use (ad libitum)

Eligibility Criteria

• Age: 21 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Community sample of healthy, regular cannabis users in the Boulder/Denver areas.

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

Contact the study team to discuss eligibility requirements. They can help determine if this study is right for you.

Sponsors & Collaborators

• L. Cinnamon Bidwell: lead
• National Institute on Drug Abuse (NIDA): collaborator

Study Sites (1)

Center for Innovation and Creativity (CINC)

Boulder, Colorado, 80301, United States

RECRUITING

Related Links

• CU Change Study Website

Biospecimen

Retention: SAMPLES WITH DNA

Blood samples collected for blood cannabinoid quantification and DNA analysis

MeSH Terms

Conditions

Marijuana Abuse

Interventions

nabiximols

Condition Hierarchy (Ancestors)

Substance-Related Disorders; Chemically-Induced Disorders; Mental Disorders

Study Officials

• Timothy Curran, Ph.D.

  University of Colorado, Boulder

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Katie N Paulich, Ph.D.

CONTACT

303-492-9549; cobra.custudy@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: June 18, 2026
• First Posted: July 1, 2026
• Study Start: December 10, 2025
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): May 31, 2027
• Last Updated: July 1, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)