Nicotinic Modulation of the Default Network

This study only enrolls healthy non-smokers. Participants perform attention tasks while undergoing functional Magnetic Resonance Imaging on three separate days. Across the three days, three difference conditions are tested in a double-blind manner, in randomized order. In all test sessions, participants receive a skin patch and swallow a capsule. In one session, both are a placebo. In another, the patch is a low-dose nicotine patch, and the capsule is a placebo. In another session, the patch is a placebo and the capsule contains a low dose of mecamylamine.

Inclusion criteria

• Age 21 through 50.
• Did not consume cigarettes, cigarillos, cigars, or other tobacco or nicotine-containing products more than 20 times in lifetime, and did not use any nicotine-containing product at all within the last two years.
• Normal or corrected to normal vision (at least 20/80).

Exclusion criteria

• Presence of metal objects in the body, implanted electronic devices, or any other counter indication for MRI.
• Claustrophobia.
• Major psychiatric disorders including mood, anxiety or psychotic disorders.
• Cardiovascular or cerebrovascular disease, such as history of myocardial infarction, heart failure, angina, stroke, severe arrhythmias, or EKG abnormalities.
• Kidney or liver disease.
• Hypertension (resting systolic BP above 140 or diastolic above 85 mm Hg).
• Hypotension (resting systolic BP below 95 or diastolic below 60).
• Use of any prescription or over-the-counter drug other than supplements and birth control.
• History of or current neurological illnesses, such as stroke, seizures, dementia or organic brain syndrome.
• Learning disability, attention deficit disorder, or any other condition that impedes memory and attention.
• Glaucoma, organic pyloric stenosis, uremia or renal insufficiency.
• Prostatic hypertrophy, bladder neck obstruction or urethral stricture.
• Left-handed or ambidextrous.
• Pregnant as determined by urine test, or breast-feeding.
• History or current diagnosis of drug or alcohol abuse or dependence.
• IQ < 85 as estimated by the WASI vocabulary subtest.