title: The Neurobiology Shaping Affective Touch: Expectation, Motivation, and Meaning in the Multisensory Context.
abstract: Inter-individual touch can be a desirable reward that can both relieve negative affect and evoke strong feelings of pleasure. However, if other sensory cues indicate it is undesirable to interact with the toucher, the affective experience of the same touch may be flipped to disgust. While a broad literature has addressed, on one hand the neurophysiological basis of ascending touch pathways, and on the other hand the central neurochemistry involved in touch behaviors, investigations of how external context and internal state shapes the hedonic value of touch have only recently emerged. Here, we review the psychological and neurobiological mechanisms responsible for the integration of tactile "bottom-up" stimuli and "top-down" information into affective touch experiences. We highlight the reciprocal influences between gentle touch and contextual information, and consider how, and at which levels of neural processing, top-down influences may modulate ascending touch signals. Finally, we discuss the central neurochemistry, specifically the μ-opioids and oxytocin systems, involved in affective touch processing, and how the functions of these neurotransmitters largely depend on the context and motivational state of the individual.
authors.affiliation: MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical SchoolBoston, MA, USA; Department of Psychology, University of OsloOslo, Norway.
authors.forename: Dan-Mikael
authors.initials: DM
authors.lastname: Ellingsen
authors.affiliation: Department of Psychology, University of Oslo Oslo, Norway.
authors.forename: Siri
authors.initials: S
authors.lastname: Leknes
authors.affiliation: Department of Psychology, University of Oslo Oslo, Norway.
authors.forename: Guro
authors.initials: G
authors.lastname: Løseth
authors.affiliation: Institute of Neuroscience and Physiology, University of Gothenburg Gothenburg, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Wessberg
authors.affiliation: Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Olausson
keywords: hedonics; opioids; oxytocin; placebo effect; social processing; top–down modulation; touch