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Drug- and reward-induced hedonic processing in humans (completed)

Benzodiazepines and minor opiates are two of the most frequently prescribed addictive drugs, and abuse of these substances is associated with a range of adverse consequences, including anhedonia, or the loss of ability to experience pleasure, as well as psychosocial problems

About the Project

The understanding of the underlying neurobiological processes has made great progress in the past 30 years and several influential theories of addiction have been proposed, but these still rely heavily on findings from research on rodents which have not been examined in humans, let alone in clinical populations. Thus, the primary objective of this project is to close this knowledge gap about drug- and reward-induced hedonic processes in humans. To this end, healthy human volunteers will be tested on a battery of reward tasks, involving both consummatory (taste, touch, money, relief) and conditioned stimuli to assess each individual's state and "hedonic capacity profile".

Outcome measures are subjective ratings of hedonic experience, in combination with objective physiological measures of autonomic arousal, subconscious affective reactions, and brain activation assessed with functional MRI. Furthermore, pharmacological interventions will clarify the role of addictive drugs and endogenous opioid and oxytonergic neurotransmitter signalling for the various reward processes. Understanding whether the role of these systems in human reward processing is homologous to that observed in rodent studies is essential for assessing current theories of addiction.

A special focus is placed on the role of social functioning and social rewards with relevance to addiction, through the use of interpersonal touch paradigms as well as intranasal oxytocin administration. This project in healthy volunteers will form the basis for further research investigating these processes in human addiction.


The Research Council of Norway (RUSMIDDEL - Researcher project) 2010 - 2017.


  • Eikemo, Marie Helene; Løseth, Guro Engvig; Johnstone, Tom; Gjerstad, Johannes; Willoch, Frode & Leknes, Siri (2016). Sweet taste pleasantness is modulated by morphine and naltrexone. Psychopharmacology. ISSN 0033-3158. 233(21), p. 13711–3723. doi: 10.1007/s00213-016-4403-x.
  • Chelnokova, Olga V; Laeng, Bruno; Løseth, Guro Engvig; Eikemo, Marie Helene; Willoch, Frode & Leknes, Siri (2016). The µ-Opioid System Promotes Visual Attention to Faces and Eyes. Social Cognitive & Affective Neuroscience. ISSN 1749-5016. 11(12), p. 1902–1909. doi: 10.1093/scan/nsw116.
  • Jonassen, Rune; Chelnokova, Olga V; Harmer, Catherine; Leknes, Siri & Landrø, Nils Inge (2015). A single dose of antidepressant alters eye-gaze patterns across face stimuli in healthy women. Psychopharmacology. ISSN 0033-3158. 232(5), p. 953–958. doi: 10.1007/s00213-014-3729-5.
  • Johnsen, Elin Follaug; Leknes, Siri; Wilson, Steven Ray Haakon & Lundanes, Elsa (2015). Liquid chromatography-mass spectrometry platform for both small neurotransmitters and neuropeptides in blood, with automatic and robust solid phase extraction. Scientific Reports. ISSN 2045-2322. 5. doi: 10.1038/srep09308. Full text in Research Archive
  • Ellingsen, Dan Mikael; Wessberg, Johan; Chelnokova, Olga V; Olausson, Håkan; Laeng, Bruno & Leknes, Siri Graff (2014). In touch with your emotions: Oxytocin and touch change social impressions while others' facial expressions can alter touch. Psychoneuroendocrinology. ISSN 0306-4530. 39(1), p. 11–20. doi: 10.1016/j.psyneuen.2013.09.017.
  • Leknes, Siri & Bastian, Brock (2014). The Benefits of Pain. Review of Philosophy and Psychology. ISSN 1878-5158. 5(1), p. 57–70. doi: 10.1007/s13164-014-0178-3.
  • Leknes, Siri & Bastian, Brock (2014). How does pain affect eating and food pleasure? Pain. ISSN 0304-3959. 155(4), p. 652–653.
  • Bastian, Brock; Jetten, Yolanda; Hornsey, Matthew & Leknes, Siri (2014). The Positive Consequences of Pain: A Biopsychosocial Approach. Personality and Social Psychology Review. ISSN 1088-8683. 18(3), p. 256–279. doi: 10.1177/1088868314527831.
  • Løseth, Guro Engvig; Ellingsen, Dan Mikael & Leknes, Siri (2014). State-dependent μ-opioid modulation of social motivation. Frontiers in Behavioral Neuroscience. ISSN 1662-5153. 8. doi: 10.3389/fnbeh.2014.00430.
  • Leknes, Siri Graff; Wessberg, Johan; Ellingsen, Dan Mikael; Chelnokova, Olga V; Olausson, Håkan & Laeng, Bruno (2013). Oxytocin enhances pupil dilation and sensitivity to hidden emotional expressions. Social Cognitive & Affective Neuroscience. ISSN 1749-5016. 8(7), p. 741–749. doi: 10.1093/scan/nss062.
  • Ellingsen, Dan Mikael; Wessberg, Johan; Eikemo, Marie Helene; Liljencrantz, Jaquette; Endestad, Tor & Olausson, Håkan [Show all 7 contributors for this article] (2013). Placebo improves pleasure and pain through opposite modulation of sensory processing. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 110(44), p. 17993–17998. doi: 10.1073/pnas.1305050110.
  • Leknes, Siri Graff; Berna, Chantal; Lee, Michael; Snyder, Gregory; Biele, Guido & Tracey, Irene (2013). The importance of context: When relative relief renders pain pleasant. Pain. ISSN 0304-3959. 154(3), p. 402–410. doi: 10.1016/j.pain.2012.11.018.
  • Wanigasekera, Vishvarani; Lee, Michael; Rogers, Richard; Kong, Yazhuo; Leknes, Siri Graff & Andersson, Jesper [Show all 7 contributors for this article] (2012). Baseline reward circuitry activity and trait reward responsiveness predict expression of opioid analgesia in healthy subjects. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 109(43), p. 17705–17710. doi: 10.1073/pnas.1120201109.

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  • Chelnokova, Olga V; Laeng, Bruno; Eikemo, Marie Helene; Riegels, Jeppe; Løseth, Guro & Maurud, Hedda [Show all 8 contributors for this article] (2014). Rewards of beauty: The opioid system mediates social motivation in humans. Molecular Psychiatry. ISSN 1359-4184. 19(7), p. 746–747. doi: 10.1038/mp.2014.1.
  • Ellingsen, Dan Mikael & Leknes, Siri (2014). Kan vi snu smerteopplevelsen fra vond til god? Forventninger, kontekst og lettelse påvirker smerte. Best Practice Nordic. ISSN 1902-7583. 9, p. 6–7.
  • Chelnokova, Olga V; Laeng, Bruno; Riegels, Jeppe; Løseth, Guro Engvig; Eikemo, Marie Helene & Leknes, Siri Graff (2013). THE HUMAN OPIOID SYSTEM MEDIATES ATTENTION TO OTHERS' EYES. Journal of Cognitive Neuroscience. ISSN 0898-929X. p. 216–216.
  • Leknes, Siri; Berna, Chantal; Lee, M; Snyder, G.; Biele, Guido & Tracey, Irene (2013). Response to the commentary “Multiple potential mechanisms for context effects on pain”. Pain. ISSN 0304-3959. 154(8), p. 1485–1486. doi: 10.1016/j.pain.2013.04.002.
  • Løseth, Guro Engvig; Ellingsen, Dan-Mikael & Leknes, Siri (2013). Touch and Pain. In: Noba textbook series: Psychology. Edited by R. Biswas-Diener & E. Diener.
  • Ellingsen, Dan-Mikael & Leknes, Siri (2013). Placebo gav lindrad smärta, men också ökad njutning. Läkartidningen. ISSN 0023-7205. 110.
  • Leknes, Siri Graff & Laeng, Bruno (2009). Social touch: investigating the role of oxytocin for interactions in the hedonic experience of touch and emotion. SFN Abstract Viewer/Itinerary Planner.

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Published Oct. 24, 2016 2:47 PM - Last modified Oct. 16, 2017 7:44 PM