Effects of caffeine on learning in healthy adults using brain imaging

Measure Striatal Adenosine-dopamine Receptors Interactions: from Molecule to Behaviors

This study tests how caffeine affects learning and brain activity in healthy adults by comparing its effects to a placebo during tasks that involve rewards.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 12 (estimated)
• Ages: 18 Years to 45 Years
• Sex: All
• Sponsor: Martinos Center for Biomedical Imaging (Academic / other)
• Drugs / interventions: radiation
• Locations: 1 site (Charlestown, Massachusetts)
• Trial ID: NCT06763172 on ClinicalTrials.gov

What this trial studies

This research investigates how caffeine intake influences the learning process through reward feedback in healthy adults. Participants will engage in reinforcement learning and motor inhibition tasks while undergoing brain scans using PET and MRI technology. The study aims to elucidate the mechanisms by which caffeine affects dopamine signaling and cognitive functions related to learning. By comparing the effects of caffeine to a placebo, the researchers hope to gain insights into the role of adenosine and dopamine interactions in reinforcement learning.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 18 to 45 who consume moderate amounts of caffeine daily.

Not a fit: Patients with a history of psychiatric or neurological disorders, or those with certain medical conditions, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance our understanding of caffeine's impact on cognitive functions, potentially leading to improved strategies for learning and behavior modification.

How similar studies have performed: While some studies have explored caffeine's effects on cognition, this specific approach using PET/MRI to investigate reinforcement learning is relatively novel.

Eligibility 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)

Where this trial is running

Charlestown, Massachusetts

• Athinoula A. Martinos Center for Biomedical Imaging — Charlestown, Massachusetts, United States (Recruiting)

Study contacts

• Study coordinator: Hsiao-Ying Wey, PhD

Conditions Healthy; Caffeine; Adenosine; Dopamine D2/3 Receptor Availability; PET/fMRI