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Effects of Caffeine on Reinforcement Learning in Healthy Adults Using PET/MRI

Hsiao-Ying Wey · NCT06763172

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Opens the official ClinicalTrials.gov record, with the study team’s contacts. Bored Studies doesn’t enroll anyone.

Key facts

Compensation
Not posted. Ask the study team before screening.
Who can join
Ages 18–45 · All sexes
Healthy volunteers
Accepted
Study type
Interventional · Phase 4
Target enrollment
12
US sites recruiting
1
Study start
May 17, 2023
Record last updated
January 9, 2025

Status re-checked against ClinicalTrials.gov within the last 12 hours.

What the study is about

This research study aims to determine whether and how caffeine intake affects learning process through reward feedback compared to placebo. The data acquired from this study would improve our understanding on the consequence and mechanism of caffeine intake in the aspect of learning process.

Participants will perform a reinforcement learning task (i.e. Probabilistic Selection Task) and a motor inhibition task (i.e. Go/NoGo task) in a brain scan. The scan will be done with the Siemens Biograph mMR positron emission tomography (PET)/ magnetic resonance imaging (MRI) 3 Tesla scanner. The PET allows us to see the changes in the "reward signals" - dopamine - in the brain using a radioactive dye called [11C]Raclopride. The MRI, on the other hand, enables us to take detailed pictures of the brain activities during cognitive tasks using a high-powered magnet. Reviewing these pictures will help us understand the influence of caffeine on reward signals and brain activities during the learning process.

Being studied: Caffeine (200 mg); Placebo

Conditions: Healthy; Caffeine; Adenosine; Dopamine D2/3 Receptor Availability

Eligibility criteria

Copied from the official record. The study team makes the final decision at screening.

Show full criteria

Inclusion Criteria

  • Age ≥ 18 and ≤ 45.
  • Habitual caffeine intake ≥ 100 mg and ≤ 450 mg daily.
  • Non-smokers.
  • Clinically healthy.
  • Have normal vision or corrected to normal vision.

Exclusion Criteria

  • Pregnant or lactating women.
  • Women using hormonal contraceptives.
  • BMI \< 18.5 or > 29.9
  • Sleep disturbance or extreme chronotype.
  • Urine test positive on one of the following substances: benzoylecgonine, morphine, d-Methamphetamine, d-Amphetamine, Benzodiazepines, Secobarbital, Methadone, Buprenorphine Glucuronide, Nortriptyline, MDMA, Oxycodone, PCP, Propoxyphene, and Cannabis/THC
  • Diagnosis of depression, anxiety, psychosis, or neurologic disorders in the last 5 years.
  • Heart or cardiovascular diseases.
  • Diabetes or other metabolic diseases.
  • Under chronic medications, for instance, painkiller and steroid.
  • Allergy to lactose (main ingredient of blank control dose)
  • Incapable to operate the tasks or comprehend the study information in English.

General MRI and PET safety exclusion criteria for all subjects:

  • Metallic foreign bodies such as cardiac pacemakers, perfusion pumps, aneurysm clips, metallic tattoos anywhere on the body, tattoos near the eye.
  • Pre-existing medical conditions including a likelihood of developing seizures or claustrophobic reactions
  • Inability to lie flat on scanner bed for about 90 min as assessed by physical examination and medical history (e.g. arthritis)
  • Recent exposure to radiation (i.e., PET from other research studies) that, when combined with this study, would be above the allowable limits
  • Pregnancy or breastfeeding: A negative serum or urine pregnancy test is required on the day of the PET procedure
  • Body weight of > 300 lbs (weight limit of the MRI scanner table)

Recruiting US locations

  • Athinoula A. Martinos Center for Biomedical Imaging

    Charlestown, MA 02129

    Site contact: Hsiao-Ying Wey, PhD · 617-724-1384 · hsiaoying.wey@mgh.harvard.edu

Study contacts (from the official record)

  • Hsiao-Ying Wey, PhD · 6177241384 · hsiaoying.wey@mgh.harvard.edu
All healthy volunteers studies in Massachusetts →
Effects of Caffeine on Reinforcement Learning in Healthy Adults… (NCT06763172) | Bored Studies