Dysphoria is associated with reduced cardiac vagal withdrawal during the imagery of pleasant scripts: Evidence for the positive attenuation hypothesis

The present study investigated emotional responding in dysphoric individuals. Dysphoric (N = 25) andnondysphoric (N = 29) individuals completed an emotional imagery task, including pleasant, neutral andunpleasant emotional-eliciting scripts. Self-reported valence and arousal, and measures of cardiac auto-nomic activity were collected during the task. Compared to nondysphoric controls, dysphoric individualsshowed a reduced heart rate increase to pleasant scripts. Less vagal withdrawal in response to pleas-ant scripts was also found in dysphoric, but not in nondysphoric, individuals. Conversely, no differencesbetween groups in autonomic responding to unpleasant scripts and in subjective measures were noted.Overall, our data showed that dysphoria is characterized by blunted cardiac autonomic reactivity inresponse to positive rather than negative emotional stimuli. The present findings also suggest that thelack of vagal suppression may reflect a reduced sensitivity to positive environmental stimuli, which, inturn, has been implicated in the development of major depression in dysphoric individuals.