She will examine the horse-human interaction, and how EAS affects both humans and horses during these types of interventions. The population that Ms. Rankins is currently recruiting are male combat veterans who served in the Iraq or Afghanistan theaters of operation. This group has been selected in order to reduce variability in the measured variables, which include hormones that differ between males and females, and selecting the most recent theaters of operation in order to remove variables that come with the passage of time.