Psychopharmacological Manipulations of Fear vs. Anxiety

Background: Stress and anxiety can interfere with how well people perform tasks. But performing a task can sometimes lessen anxiety by distracting people from the stress. Researchers want to examine the interaction between attention and stress. They will use two drugs with different effects on stress and concentration. Objective: - To better understand how thinking and emotion affect anxiety and performance. Also, to study the effects of methylphenidate and propranolol on performance. Eligibility: - Adults age 18 50. Design: - First, participants will be screened with a test in which they hear loud, sudden noises through headphones. Sticky pad electrodes will be placed on the skin under one eye. These electrodes will tell us how sensitive participants are to the noises. - Second, participants will complete questionnaires about their mood, thinking, and anxiety. They will give a saliva sample. For this, a cotton swab will be placed in their mouth for 2 minutes. - Third, participants will take a single dose of one of the study pills or a placebo. They will then look at words, shapes, and letters on a computer monitor. They will answer questions about what they remember. They may receive a shock or hear loud noises during the tests. - For the shocks, small metal disk or sticky pad electrodes will be taped to a wrist or finger. For recording bodily responses, additional electrodes will be placed on the arms, body, and under each eye. - Blood pressure and pulse will be measured during the tests. More saliva samples will be taken. - At the end of the study, participants will answer questions about their reaction to the study testing and about any effects they noticed from the study pill. - After the experiment, participants will be evaluated for effects of the study pill.