Brain Imaging Changes in Fear and Anxiety

Study Summary

The purpose of this study is to use brain imaging technology to investigate brain changes in people exposed to predictable versus unpredictable unpleasant stimuli. Unpleasant events that can be predicted evoke a response of fear, whereas unpredictable, unpleasant stimuli cause chronic anxiety not associated with a specific event. Information gained from this study may help in the development of more effective treatments for anxiety disorders. When confronted with fearful events, people eventually develop fear of specific cues that were associated with these events as well as to the environmental context in which the fearful event occurred. Evidence suggests that cued fear and contextual fear model different aspects of anxiety. However, studies that examine the way the brain affects expression of contextual fear have not been conducted. This study will use magnetic resonance imaging (MRI) or Magneto-encephalography (MEG) to compare the brain activity underlying fear brought on by predictable and unpredictable aversive stimuli.

Primary Outcome

The average bed nucleus of the stria terminalis (BNST) correlations between all averaged time series were extracted from the raters' individual masks. Blood Oxygenation Level Dependent (BOLD) signals were used to extract a mean time series from the BNST masks. This time series was correlated across the rest of the brain using 3dTcorr1D, which computes the correlation coefficient between each voxel time series. Raters were blinded to subject identity for subjective sensory effects at high field a

Interventions

• DEVICE Shock device
• DEVICE Acoustic startle