Blocking opioids attenuates physical warmth-induced feelings of social connection.

Abstract

“Heartwarming” social experiences, when one feels interpersonally connected to others, have recently been linked with physical warmth. According to one theory (Panksepp, 1998), “social warmth” and physical warmth may be closely linked because both experiences are supported by similar neurobiological mechanisms, however, the neurochemical substrates underlying this overlap have not been explored. Here, an opioid antagonist, naltrexone, was administered in order to examine the role of opioids, previously shown to alter temperature and social bonding behavior, on perceived thermal intensity, general positive affect, and feelings of social connection from physical warmth. Thirty-one participants took both naltrexone and placebo and completed a temperature manipulation task (held a warm pack, cold pack, and neutral object) while on each drug. Replicating previous research, holding a warm (vs. a cold or neutral) object increased feelings of social connection. Moreover, blocking opioids reduced this effect. Hence, naltrexone specifically reduced feelings of social connection to holding a warm (vs. neutral) object but not to holding a cold (vs. neutral) object. These results lend further support to the theory that social and physical warmth share neurobiological, opioid receptor dependent mechanisms.

Naltrexone alters the processing of social and emotional stimuli in healthy adults

“…This dose was equivalent to the dose used in most other acute studies, including the most similar study, documenting reduced wanting and liking for attractive faces (Chelnokova et al, 2014). However, in some other previous studies, NTX has been given at the same 50 mg dose, but chronically over 4 days (Inagaki et al, 2015). Chronic dosing may be necessary to reveal consistent negative effects of NTX on social pleasure.…”

“…Consistent with the proposed broader role of the mu-opiate system in pleasure (Berridge et al, 2009), these studies suggest that NTX dampens positive responses to nonsocial rewards. Only three studies have addressed the effects of NTX on positive social stimuli, specifically feelings after positive autobiographical memories combined with film clips (Schweiger, Stemmler, Burgdorf, & Wacker, 2013), feelings of social connection engendered by holding a warm object (Inagaki, Irwin, & Eisenberger, 2015), and “liking” and “wanting” responses to attractive faces (Chelnokova et al, 2014). In these three cases, NTX reduced feelings of social “warmth” and “liking”, again consistent with expected effects of mu-opioid antagonism on responses to positive social stimuli.…”

“…We studied two components of social processing: (1) seeking of social stimuli, indexed as attention to positive and negative expressions, measured using electroocu-lographic (EOG) tracking of eye movements and (2) responses to social stimuli, indexed as identification of emotional expressions and electromyographic (EMG) activity in facial muscles sensitive to emotional state during viewing of emotional expressions. Based on evidence that NTX reduces positive social responses (Chelnokova et al, 2014; Inagaki et al, 2015; Schweiger et al, 2013), we expected that NTX would impair responses to positive social stimuli, as indicated by slower identification of positive facial expressions and reduced positive psychophysiological responses to positive facial expressions. Because of the theoretically opposing effects of mu and kappa activation on anxiety and stress, we maintained an open hypothesis about the effects of NTX on responses to negative facial expressions.…”

Modernizing Relationship Therapy through Social Thermoregulation Theory: Evidence, Hypotheses, and Explorations

“…Given the discussion on power in psychological science, it may then also not come as a surprise that also in the field of thermoregulation some effects failed to replicate (Vess, 2012;LeBel and Campbell, 2013). Yet, other effects did replicate (IJzerman and Semin, 2009;Schilder et al, 2014;Inagaki et al, 2015;Ebersole et al, 2016;IJzerman et al, 2016). Further, original studies with larger Ns do exist, with some studies with participant samples between 100 and 500 (e.g., IJzerman et al, 2015b;Van Acker et al, 2016), and some outliers even with samples around 30,000 (Hong and Sun, 2012) and above 6 million (Zwebner et al, 2013).…”

Gene expression correlates of social evolution in coral reef butterflyfishes

“…http://dx.doi.org/10.1101/214759 doi: bioRxiv preprint first posted online Nov. 6, 2017; the implicated brain regions involved share some similarities with those implicated in C. lunulatus and established in M. ochrogaster. Specifically, fMRI studies suggest that in humans, motivational aspects of partner preference formation are regulated by the dorsal striatum 206 , which is rich in MORs 210 . Whereas, the positive hedonics of "romantic love" are associated with the AMY, septal fornix, and VTA 190,192 , all of which are also rich in MORs 211,212 .…”