Morphine reduced perceived anger from neutral and implicit emotional expressions

The μ-opioid system modulates responses to pain and psychosocial stress and mediates non-social and social reward. In humans, the μ-opioid agonist morphine can increase overt attention to the eye-region and visual exploration of faces with neutral expressions. However, little is known about how the...

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Main Authors: Løseth, G, Eikemo, M, Isager, P, Holmgren, J, Laeng, B, Vindenes, V, Hjørnevik, T, Leknes, S
Format: Journal article
Published: Elsevier 2018
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author Løseth, G
Eikemo, M
Isager, P
Holmgren, J
Laeng, B
Vindenes, V
Hjørnevik, T
Leknes, S
author_facet Løseth, G
Eikemo, M
Isager, P
Holmgren, J
Laeng, B
Vindenes, V
Hjørnevik, T
Leknes, S
author_sort Løseth, G
collection OXFORD
description The μ-opioid system modulates responses to pain and psychosocial stress and mediates non-social and social reward. In humans, the μ-opioid agonist morphine can increase overt attention to the eye-region and visual exploration of faces with neutral expressions. However, little is known about how the human μ-opioid system influences sensitivity to and appraisal of subtle and explicit cues of social threats and reward. Here, we examined the effects of selective μ-opioid stimulation on perception of anger and happiness in faces with explicit, neutral or implicit emotion expressions. Sixty-three healthy adults (32 females) attended two sessions where they received either placebo or 10 mg per oral morphine in randomised order under double-blind conditions. Based on the known μ-opioid reduction of pain and discomfort, as well as reports suggesting that the non-specific partial agonist buprenorphine or the non-specific antagonist naltrexone affect appraisal of social emotional stimuli, we hypothesised that morphine would reduce threat sensitivity and enhance perception of happy facial expressions. While overall perception of others’ happiness was unaffected by morphine treatment, morphine reduced perception of anger in stimuli with neutral and implicit expressions without affecting perception of explicit anger. This effect was statistically unrelated to gender, subjective drug effects, mood and autism trait measures. The finding that a low dose of μ-agonist reduced the propensity to perceive anger in photos with subtle facial expressions is consistent with the notion that μ-opioids mediate social confidence and reduce sensitivity to threat cues.
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spelling oxford-uuid:8fe38a9e-858b-4102-b0ac-ecce7426d1732022-03-26T23:07:34ZMorphine reduced perceived anger from neutral and implicit emotional expressionsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:8fe38a9e-858b-4102-b0ac-ecce7426d173Symplectic Elements at OxfordElsevier2018Løseth, GEikemo, MIsager, PHolmgren, JLaeng, BVindenes, VHjørnevik, TLeknes, SThe μ-opioid system modulates responses to pain and psychosocial stress and mediates non-social and social reward. In humans, the μ-opioid agonist morphine can increase overt attention to the eye-region and visual exploration of faces with neutral expressions. However, little is known about how the human μ-opioid system influences sensitivity to and appraisal of subtle and explicit cues of social threats and reward. Here, we examined the effects of selective μ-opioid stimulation on perception of anger and happiness in faces with explicit, neutral or implicit emotion expressions. Sixty-three healthy adults (32 females) attended two sessions where they received either placebo or 10 mg per oral morphine in randomised order under double-blind conditions. Based on the known μ-opioid reduction of pain and discomfort, as well as reports suggesting that the non-specific partial agonist buprenorphine or the non-specific antagonist naltrexone affect appraisal of social emotional stimuli, we hypothesised that morphine would reduce threat sensitivity and enhance perception of happy facial expressions. While overall perception of others’ happiness was unaffected by morphine treatment, morphine reduced perception of anger in stimuli with neutral and implicit expressions without affecting perception of explicit anger. This effect was statistically unrelated to gender, subjective drug effects, mood and autism trait measures. The finding that a low dose of μ-agonist reduced the propensity to perceive anger in photos with subtle facial expressions is consistent with the notion that μ-opioids mediate social confidence and reduce sensitivity to threat cues.
spellingShingle Løseth, G
Eikemo, M
Isager, P
Holmgren, J
Laeng, B
Vindenes, V
Hjørnevik, T
Leknes, S
Morphine reduced perceived anger from neutral and implicit emotional expressions
title Morphine reduced perceived anger from neutral and implicit emotional expressions
title_full Morphine reduced perceived anger from neutral and implicit emotional expressions
title_fullStr Morphine reduced perceived anger from neutral and implicit emotional expressions
title_full_unstemmed Morphine reduced perceived anger from neutral and implicit emotional expressions
title_short Morphine reduced perceived anger from neutral and implicit emotional expressions
title_sort morphine reduced perceived anger from neutral and implicit emotional expressions
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AT hjørnevikt morphinereducedperceivedangerfromneutralandimplicitemotionalexpressions
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