We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleOrienting in a defensive world: mammalian modifications of our evolutionary heritage. A Polyvagal Theory.AuthorsPorges SWPublicationPsychophysiology, 1995, Vol 32, Issue 4, p301ISSN0048-5772Publication typearticleDOI10.1111/j.1469-8986.1995.tb01213.x