Effects of intranasal oxytocin and vasopressin on cooperative behavior and associated brain activity in men

• Type of Material: Article
• Authors: James K Rilling, Emory University; Ashley C. DeMarco, Emory University; Patrick D. Hackett, Emory University; Richmond Thompson, Bowdoin College; Beate Ditzen, Emory University; Rajan Patel, Emory University; Giuseppe Pagnoni, University of Modena and Reggio Emilia
• Language: English
• Date: 2012-04
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2011 Elsevier Ltd. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.psyneuen.2011.07.013
• Title of Journal or Parent Work: Psychoneuroendocrinology
• ISSN: 0306-4530
• Volume: 37
• Issue: 4
• Start Page: 447
• End Page: 461
• Grant/Funding Information: Funding for this study was provided by NIMH Grant R01 MH084068-01A1
• Keywords: cooperation; oxytocin; vasopressin; fMRI
• Research Categories: Biology, Neuroscience; Psychology, Behavioral

Abstract

The neural mechanisms supporting social bonds between adult men remain uncertain. In this double-blind, placebo-controlled study, we investigate the impact of intranasally administered oxytocin (OT) and vasopressin (AVP) on behavior and brain activity among men in the context of an iterated Prisoner’s Dilemma game, which models a real-life social situation. fMRI results show that, relative to both AVP and placebo, OT increases the caudate nucleus response to reciprocated cooperation, which may augment the reward of reciprocated cooperation and/or facilitate learning that another person can be trusted. OT also enhances left amygdala activation in response to reciprocated cooperation. Behaviorally, OT was associated with increased rates of cooperation following unreciprocated cooperation in the previous round compared with AVP. AVP strongly increased cooperation in response to a cooperative gesture by the partner compared with both placebo and OT. In response to reciprocated cooperation, AVP increased activation in a region spanning known vasopressin circuitry implicated in affiliative behaviors in other species. Finally, both OT and AVP increase amygdala functional connectivity with the anterior insula relative to placebo, which may increase the amygdala’s ability to elicit visceral somatic markers that guide decision making. These findings extend our knowledge of the neural and behavioral effects of OT and AVP to the context of genuine social interactions.