<qa>  What is the goal of this preliminary study?This preliminary study is expected to lay the groundwork for a larger study of the early impact of traumatic events on psychophysiological and psychological processes. In the long-term, we expect to 1 better characterize the onset of symptoms and their evolution over time following trauma, 2 identify psychophysiological markers for PTSD, 3 identify ASD victims at-risk for PTSD, and 4 improve our ability to prevent the development of chronic psychopathology following trauma. 