Public and private heart rate feedback in social phobia: a manipulation of anxiety visibility.

According to cognitive behavioural models of social phobia, bodily symptoms are the main source of information concerning social evaluation for social phobics. Experience and perception of bodily symptoms therefore play an important role in social anxiety. In this study we evaluated the effects of anxiety visibility on patients and controls using feedback of veridical heart sounds. A total of 32 social phobics and 32 controls were asked twice to sit in a chair and appear relaxed while being evaluated. Half of the participants heard their heart sounds first via headphones and then via loudspeakers which were also audible to observers. The presentation order of the heart sound was reversed for the other half of the subjects. Social phobics reported substantially more anxiety than controls. Both groups showed habituation in heart rate from the first to the second presentation, and both groups reported perception of a higher heart rate, but only social phobics reported significantly more anxiety and were more worried about their heart rates in the public than in the private condition. These effects were in excess of actual heart rate differences. In conclusion, social phobics worried about the broadcast of a bodily anxiety symptom, whereas controls did not. Information about arousal made public has a strong potential to increase anxiety levels in social phobics.