<qa>  What is the name of the study that Drs. Osuch and Ursano haveAcute stress disorder ASD and posttraumatic stress disorder PTSD are common consequences of exposure to traumatic events. Despite growing evidence of neurobiological dysfunction in ASD and PTSD, the pathogenesis of these disorders is still unknown. Drs. Osuch and Ursano Uniformed Services University of the Health Sciences have received support to conduct a 14-week study that will investigate the efficacy of the serotonergic medication sertraline Zoloft in the treatment and prevention of posttraumatic psychiatric sequelae in ASD victims. The present project is an amendment to Drs. Osuch and Ursanos study. It will attempt to identify early psychological and neurobiological abnormalities in ASD. More specifically, the present project will examine to what extent sensitization and conditioning processes, as well as emotional dysregulation, contribute to ASD. We also propose to investigate the potential association between cerebellum dysfunction and peritraumatic dissociations. To accomplish this goal, a series of three experiments will be implemented to investigate: 1 the symptom of exaggerated startle; 2 emotional reactivity to trauma-related and trauma-unrelated cues; and 3 cerebellum functioning using eyeblink conditioning. This study will inform on the short-term consequences of trauma, will help identify potential psychophysiological markers of ASD that emerge following trauma, and will examine the effects of an SSRI on preventing trauma-related neurobiological deficits. 