title: Interoception, homeostatic emotions and sympathovagal balance.
abstract: We briefly review the evidence for distinct neuroanatomical substrates that underlie interoception in humans, and we explain how they substantialize feelings from the body (in the insular cortex) that are conjoined with homeostatic motivations that guide adaptive behaviours (in the cingulate cortex). This hierarchical sensorimotor architecture coincides with the limbic cortical architecture that underlies emotions, and thus we regard interoceptive feelings and their conjoint motivations as homeostatic emotions We describe how bivalent feelings, emotions and sympathovagal balance can be organized and regulated efficiently in the bicameral forebrain as asymmetric positive/negative, approach/avoidance and parasympathetic/sympathetic components. We provide original evidence supporting this organization from studies of cardiorespiratory vagal activity in monkeys and functional imaging studies in healthy humans showing activation modulated by paced breathing and passively viewed emotional images. The neuroanatomical architecture of interoception provides deep insight into the functional organization of all emotional feelings and behaviours in humans.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
authors.affiliation: Research Service, San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121, USA irina.strigo@ucsf.edu.|Department of Psychiatry, University of California San Francisco, San Francisco, CA 94121, USA.
authors.forename: Irina A
authors.identifier: 0000-0002-8799-716X
authors.initials: IA
authors.lastname: Strigo
authors.affiliation: Neurosurgery Research, Barrow Neurological Institute, Phoenix, AZ 85013, USA arthur.craig@dignityhealth.org.
authors.forename: Arthur D Bud
authors.initials: AD
authors.lastname: Craig
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004644:Emotions; D006179:Gyrus Cinguli / Q000502:physiology*; D006706:Homeostasis; D006801:Humans; D065812:Interoception; D008251:Macaca / Q000502:physiology*
keywords: 
  asymmetry; anterior cingulate; insula; respiration; vagus