AFFECTIVE VALENCE AND AROUSAL IN ADHD AND NORMAL BOYS DURING A STARTLE HABITUATION EXPERIMENT

Objective: To measure two dimensions of emotion (affective valence and arousal) in 29 boys with attention-deficit hyperactivity disorder (AD HD) and 32 normal bays. Method: After a startle habituation experiment during which these subjects heard 40 startling sounds while watching a silent interesting movie, they were asked 12 questions (categorized a priori into questions relating to affective valence and to arousal) about their emotional reactions to these putatively unpleasant and ple asurable stimuli. Responses were recorded for the two dimensions of em otion, using two cartoon strips in each of which five expressions of a cartoon character varied linearly from happy to unhappy (affective va lence dimension) and calm to excited (arousal dimension). Results: Fac tor analyses of the 12 responses revealed four factors in which the hi ghest loadings were far affective valence to the startle responses, af fective valence to the silent movie, arousal, and scary feelings. Rela tive to the normal group, the responses of the ADHD group were signifi cantly biased toward pleasurable valence to the startling stimuli and to the silent movie, with a trend toward hypoarousal. Startle magnitud e and habituation were similar in both groups. The normal tonic heart rate acceleration throughout ?he experimental session was not sustaine d in the ADHD group. Conclusions: The seif-reports of affective valenc e biased in the direction of pleasure and away from displeasure and th e trend toward hypoarousal suggest an emotional dysfunction in ADHD.