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- Crucianelli, Laura, et al.
(author)
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Interoception as independent cardiac, thermosensory, nociceptive, and affective touch perceptual submodalities
- 2022
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In: Biological Psychology. - Stockholm : Karolinska Institutet, Dept of Neuroscience. - 0301-0511 .- 1873-6246.
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Journal article (peer-reviewed)abstract
- Interoception includes signals from inner organs and thin afferents in the skin, providing information about the body’s physiological state. However, the functional relationships between interoceptive submodalities are unclear, and thermosensation as skin-based interoception has rarely been considered. We used five tasks to examine the relationships among cardiac awareness, thermosensation, affective touch, and nociception. Thermosensation was probed with a classic temperature detection task and the new dynamic thermal matching task, where participants matched perceived moving thermal stimuli in a range of colder/warmer stimuli around thermoneutrality. We also examined differences between hairy and non-hairy skin and found superior perception of dynamic temperature and static cooling on hairy skin. Notably, no significant correlations were observed across interoceptive submodality accuracies (except for cold and pain perception in the palm), which indicates that interoception at perceptual levels should be conceptualised as a set of relatively independent processes and abilities rather than a single construct.
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- Enmalm, Adam, et al.
(author)
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Body Perception and Social Touch Preferences in Times of Grief
- 2024
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In: Journal of loss & trauma. - : TAYLOR & FRANCIS INC. - 1532-5024 .- 1532-5032.
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Journal article (peer-reviewed)abstract
- Grief is a core human experience. The time following the loss of a loved one is associated with an increased risk for negative health outcomes. Yet, only a few studies investigate bodily consequences of grief and consoling behaviors, specifically the potentially supportive role of interpersonal touch during grief. We conducted an online-study where participants filled in questionnaires and rated videos of short touch gestures and interactions. People who lost a loved one within the last 2 years were asked about their grief experiences and to rate the different types of touch from the perspective of a receiver. People who had not lost a close person in the last 2 years rated the touch from the perspective of providing touch to a grieving individual. The majority of the recent-loss sample reported to have perceived their own body and bodily states less after the loss. Two-thirds reported feeling the presence of the deceased at least once. Grief-sensations were experienced mostly in the chest and upper body, the same areas where the consoling effect of a hug was perceived. Overall, the recent-loss group reported amounts of wanting of the vicarious touch gestures similar to the endorsement by people taking the active touching perspective. However, discrepancies between groups were found for some types of touch, including slow affective stroking. These results contribute to a deeper understanding of the body and bodily interactions like social touch in grief and consolation. Our findings can be seen as a first point of reference on how to interact with grieving individuals and could contribute to novel interventions for individuals with prolonged grief disorder.
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3. |
- Kaldewaij, Reinoud, et al.
(author)
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Ketamine reduces the neural distinction between self- and other-produced affective touch: a randomized double-blind placebo-controlled study
- 2024
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In: Neuropsychopharmacology. - : SPRINGERNATURE. - 0893-133X .- 1740-634X.
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Journal article (peer-reviewed)abstract
- A coherent sense of self is crucial for social functioning and mental health. The N-methyl-D-aspartate antagonist ketamine induces short-term dissociative experiences and has therefore been used to model an altered state of self-perception. This randomized double-blind placebo-controlled cross-over study investigated the mechanisms for ketamine's effects on the bodily sense of self in the context of affective touch. Thirty healthy participants (15 females/15 males, age 19-39) received intravenous ketamine or placebo while performing self-touch and receiving touch by someone else during functional MRI - a previously established neural measure of tactile self-other-differentiation. Afterwards, tactile detection thresholds during self- and other-touch were assessed, as well as dissociative states, interoceptive awareness, and social touch attitudes. Compared to placebo, ketamine administration elicited dissociation and reduced neural activity associated with self-other-differentiation in the right temporoparietal cortex, which was most pronounced during other-touch. This reduction correlated with ketamine-induced reductions in interoceptive awareness. The temporoparietal cortex showed higher connectivity to somatosensory cortex and insula during other- compared to self-touch. This difference was augmented by ketamine, and correlated with dissociation strength for somatosensory cortex. These results demonstrate that disrupting the self-experience through ketamine administration affects neural activity associated with self-other-differentiation in a region involved in touch perception and social cognition, especially with regard to social touch by someone else. This process may be driven by ketamine-induced effects on top-down signaling, rendering the processing of predictable self-generated and unpredictable other-generated touch more similar. These findings provide further evidence for the intricate relationship of the bodily self with the tactile sense.
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