Neural Substrates of Approach-Avoidance Conflict

Background: \- People who are dependent on alcohol drink even when they know something bad might happen. Researchers want to learn more about why they do this. Objectives: \- To study brain response when a person plays a game in different threat conditions. Eligibility: * Healthy right-handed adult heavy drinkers age 21 60 * Healthy right-handed adult light drinkers age 21 60 Design: * Participants will be screened with medical history, physical exam, and blood and urine tests. They will have an EKG and psychiatric interview. * Participants will have one or two clinic visits. * Participants will be asked about their alcohol drinking. * They will choose a snack and alcoholic beverage that they must drink in 5 minutes. After their breath alcohol content (BrAC) is zero, they will play a game in the MRI scanner. * The scanner is a metal cylinder that takes pictures of the brain. Participants lie on a table that slides in and out of the cylinder. They will be in it for about 90 minutes, lying still for up to 20 minutes. * During the MRI, participants will play a simple computer game to earn food or drink points under different threats of electric shock. Points can be exchanged for food or alcohol after the game. Sometimes, participants will receive a mild electric shock through a metal disk on the wrist. Electric shocks will only happen if the participant tries to earn a reward point. * After the MRI, participants use their points for another drink and snack. They will stay at the clinic until their BrAC is low, usually within 3 hours. Participants cannot drive themselves home. * Participants will have a follow-up phone call the next day.