| 1. |
- Lasselin, Julie, et al.
(författare)
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Biological motion during inflammation in humans
- 2020
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 84, s. 147-153
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Tidskriftsartikel (refereegranskat)abstract
- Biological motion is a powerful perceptual cue that can reveal important information about the inner state of an individual. Activation of inflammatory processes likely leads to changes in gait, posture, and mobility patterns, but the specific characteristics of inflammation-related biological motion have not been characterized. The aim of this study was to determine the effect of inflammation on gait and motion in humans. Systemic inflammation was induced in 19 healthy volunteers with an intravenous injection of lipopolysaccharide (2 ng/kg body weight). Biological motion parameters (walking speed, stride length and time, arm, leg, head, and shoulder angles) were assessed during a walking paradigm and the timed-up-and-go test. Cytokine concentrations, body temperature, and sickness symptoms were measured. During inflammation, compared to placebo, participants exhibited shorter, slower, and wider strides, less arm extension, less knee flexion, and a more downward-tilting head while walking. They were also slower and took a shorter First step in the timed-up-and-go test. Higher interleukin-6 concentrations, stronger sickness symptoms, and lower body temperature predicted the inflammation-related alterations in biological motion. These findings show that biological motion contains clear information about the inflammatory status of an individual, and may be used by peers or artificial intelligence to recognize that someone is sick or contagious.
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| 2. |
- Regenbogen, C., et al.
(författare)
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Multisensory detection of sickness
- 2016
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Ingår i: XXVIth Annual Meeting of the European Chemoreception Research Organization. ; , s. 94-95
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Konferensbidrag (refereegranskat)abstract
- Converging evidence suggests that humans have a behavioral repertoire that assists the immune system in the defense against infectious disease. Behavioral detection of subtle and early sickness cues in others, and subsequent avoidance of the infected conspecific, would indeed be a cost-efficient way of coping with an environment fraught with pathogens. That humans can detect early and subtle cues of sickness by way of both olfaction and vision was recently demonstrated. The current study targeted how sickness cues affect social perception 95and how these visual and olfactory cues, alone and in unison, activate the brain.
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| 3. |
- Hansson, Lina S., 1986-, et al.
(författare)
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Pointing out sickness : Detection of sickness from gait patterns
- 2021
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 98, s. 21-21
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: The ability to detect sick individuals is crucial for survival, by allowing avoidance of contagion. We have shown that humans can detect sick individuals from facial cues and body odors, but perception of these cues requires close proximity to the infectious person. Given that gait patterns can be detected from a distance and are altered during sickness, it would be beneficial to detect sickness from biological motion. Methods: We collected videos and point-light displays of walking individuals who were either made sick experimentally with an injection of lipopolysaccharide, or who were healthy (placebo). In study 1, 106 naive subjects watched these displays and rated them as coming from someone sick or healthy. In study 2, 106 other subjects rated health, sadness and tiredness of the displays on a VAS scale. Results: In Study 1, the sensitivity was 59% for videos and 57% for point-light displays, while the specificity was 74% for videos and 61% for point-light displays. Additional results will be presented at the conference. Conclusion: This study will indicate if sickness can be detected from gait patterns, possibly adding to immune defensive behaviors by facilitating avoidance of contagious peers.
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| 4. |
- Hansson, Lina S., et al.
(författare)
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The walking sick : Perception of experimental sickness from biological motion
- 2023
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Ingår i: Brain, behavior, and immunity. - : Elsevier. - 0889-1591 .- 1090-2139. ; 113, s. 319-327
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Tidskriftsartikel (refereegranskat)abstract
- Identification of sick conspecifics allows for avoidance of infectious threats, and is therefore an important behavioral defense against diseases. Here, we investigated if humans can identify sick individuals solely from biological motion and posture (using point-light displays). Additionally, we sought to determine which movements and sickness parameters would predict such detection. We collected video clips and derived point-light displays (one stride presented in a loop) of sick walkers (injected with lipopolysaccharide at 2.0 ng/kg body weight) and the same walkers when healthy (injected with saline). We then presented these displays to two groups, one group classified each walker as sick or healthy (study 1, n = 106), and the other group scored the walkers’ health on a visual analogue scale (study 2, n = 106). The raters were able to identify sick individuals above chance, and rated sick walkers as having worse health, both from observing video clips and point-light displays. Furthermore, both sickness detection and worse apparent health were predicted by inflammation-induced increase in rigidity and slower walking, but not other cues. Altogether, these findings indicate that biological motion can serve as a sickness cue, possibly allowing humans to identify sick conspecifics from a distance, and thereby allowing for disease avoidance.
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| 5. |
- Karshikoff, B., et al.
(författare)
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Modality and sex differences in pain sensitivity during human endotoxemia
- 2014
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 46, s. 35-43
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Tidskriftsartikel (refereegranskat)abstract
- Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, and has been proposed to be central in clinical pain conditions. Women are overrepresented in many chronic pain conditions, but experimental studies on sex differences in pain regulation during systemic inflammation are still scarce. In two randomized and double blind placebo controlled experiments, we used low doses of lipopolysaccharide (LPS) as an experimental model of systemic inflammation. The first study employed 0.8ng/kg LPS in a within-subject design of 8 individuals (1 woman), and the second study 0.6ng/kg LPS in a between-subject design of 52 participants (29 women). We investigated the effect on (a) pressure, heat, and cold pain thresholds, (b) suprathreshold noxious heat and cold sensitivity, and (c) conditioned pain modulation (CPM), and differences between men and women. LPS induced significantly lower pressure pain thresholds as compared to placebo (mean change with the 0.8ng/kg dose being -64±30kPa P=.04; with the 0.6ng/kg dose -58±55kPa, P<.01, compared to before injection), whereas heat and cold pain thresholds remained unaffected (P's>.70). Suprathreshold noxious pain was not affected by LPS in men (P's⩾.15). However, LPS made women rated suprathreshold noxious heat stimuli as more painful (P=.01), and showed a tendency to rate noxious cold pain as more painful (P=.06) as compared to placebo. Furthermore, LPS impaired conditioned pain modulation, a measure of endogenous pain inhibition, but this effect was also restricted to women (P<.01, for men P=.27). Pain sensitivity correlated positively with plasma IL-6 and IL-8 levels. The results show that inflammation more strongly affects deep pain, rather than cutaneous pain, and suggest that women's pain perception and modulation is more sensitive to immune activation than men's.
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| 6. |
- Karshikoff, Bianka, et al.
(författare)
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Why sickness hurts : A central mechanism for pain induced by peripheral inflammation
- 2016
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Ingår i: Brain, behavior, and immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 57, s. 38-46
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Tidskriftsartikel (refereegranskat)abstract
- Low-grade systemic inflammation has been implicated in chronic pain, as well as in comorbid diseases like depression and fatigue. We have previously shown that women's pain perception and regulation is more affected by systemic inflammation than that of men. Here we investigated the neural substrates underlying these effects using an fMRI paradigm previously employed in a clinical population. Fifty-one participants (29 women) were injected with 0.6ng/kg lipopolysaccharide (LPS) or saline to induce a peripheral inflammatory response. The subjects were then tested with a pressure pain fMRI paradigm designed to capture descending pain inhibitory activity 2h after injection, and blood was sampled for cytokine analysis. The subjects injected with LPS became more pain sensitive compared to the placebo group, and the heightened pain sensitivity was paralleled by decreased activity in the ventrolateral prefrontal cortex and the rostral anterior cingulate cortex (rACC) compared to placebo; areas involved in descending pain regulation. The LPS group also had higher activity in the anterior insular cortex, an area underpinning affective and interoceptive pain processing. Women displayed overall less pain-evoked rACC activity compared to men, which may have rendered women less resilient to immune provocation, possibly explaining sex differences in LPS-induced pain sensitivity. Our findings elucidate the pain-related brain circuits affected by experimental peripheral inflammation, strengthening the theoretical link between systemic inflammation and weakened pain regulation in chronic pain disorders. The results further suggest a possible mechanism underlying the female predominance in many chronic pain disorders.
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