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Tina Sundelin Foto: Psykologiska institutionen/HD

Tina Sundelin

Universitetslektor

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Arbetar vid Psykologiska institutionen
E-post tina.sundelin@psychology.su.se
Besöksadress Frescati hagväg 14
Postadress Psykologiska institutionen 106 91 Stockholm

Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2019. Georgia Sarolidou (et al.). Brain, behavior, and immunity 80, 286-291

    To handle the substantial threat posed by infectious diseases, behaviors that promote avoidance of contagion are crucial. Based on the fact that sickness depresses mood and that emotional expressions reveal inner states of individuals to others, which in turn affect approach/avoidance behaviors, we hypothesized that facial expressions of emotion may play a role in sickness detection. Using an experimental model of sickness, 22 volunteers were intravenously injected with either endotoxin (lipopolysaccharide; 2 ng/kg body weight) and placebo using a randomized cross-over design. The volunteers were two hours later asked to keep a relaxed expression on their face while their facial photograph was taken. To assess the emotional expression of the sick face, 49 participants were recruited and were asked to rate the emotional expression of the facial photographs of the volunteers when sick and when healthy. Our results indicate that the emotional expression of faces changed two hours after being made temporarily sick by an endotoxin injection. Sick faces were perceived as more sick/less healthy, but also as expressing more negative emotions, such as sadness and disgust, and less happiness and surprise. The emotional expressions mediated 59.1% of the treatment-dependent change in rated health. The inclusion of physical features associated with emotional expressions to the mediation analysis supported these results. We conclude that emotional expressions may contribute to detection and avoidance of infectious individuals and thereby be part of a behavioral defense against disease.

  • 2019. Tina Sundelin (et al.). Scientific Reports 9

    Several studies suggest that sleep deprivation affects risky decision making. However, most of these are confounded by feedback given after each decision, indicating that decisions may be based on suboptimal feedback-learning rather than risk evaluation. Furthermore, few studies have investigated the effect of sleep loss on aspects of prospect theory, specifically the framing effect and probability distortion. In this within-subjects design, 25 people had (i) two nights of an 8 h sleep opportunity, and (ii) two nights of a 4 h sleep opportunity, in a counter-balanced order. Following the two nights, they performed a gambling task with no immediate feedback; for each round, they could either gamble for a full amount, or take a settlement framed as a gain or a loss for part of the amount. Sleep restriction did not significantly affect the tendency to gamble, the framing effect, or probability distortion, as compared to normal sleep. These results indicate that two nights of sleep restriction affects neither general gambling tendency, nor two of the main predictions of prospect theory. This resilience may be due to a less extreme sleep loss than in previous studies, but also indicates that learning components and risk biases should be separated when assessing the effect of sleep loss on risky behaviour.

  • 2017. Christina Regenbogen (et al.). Proceedings of the National Academy of Sciences of the United States of America 114 (24), 6400-6405

    Throughout human evolution, infectious diseases have been a primary cause of death. Detection of subtle cues indicating sickness and avoidance of sick conspecifics would therefore be an adaptive way of coping with an environment fraught with pathogens. This study determines how humans perceive and integrate early cues of sickness in conspecifics sampled just hours after the induction of immune system activation, and the underlying neural mechanisms for this detection. In a double-blind placebo-controlled crossover design, the immune system in 22 sample donors was transiently activated with an endotoxin injection [lipopolysaccharide (LPS)]. Facial photographs and body odor samples were taken from the same donors when sick (LPS-injected) and when healthy (saline-injected) and subsequently were presented to a separate group of participants (n = 30) who rated their liking of the presented person during fMRI scanning. Faces were less socially desirable when sick, and sick body odors tended to lower liking of the faces. Sickness status presented by odor and facial photograph resulted in increased neural activation of odor-and faceperception networks, respectively. A superadditive effect of olfactory-visual integration of sickness cues was found in the intraparietal sulcus, which was functionally connected to core areas of multisensory integration in the superior temporal sulcus and orbitofrontal cortex. Taken together, the results outline a disease-avoidance model in which neural mechanisms involved in the detection of disease cues and multisensory integration are vital parts.

  • 2017. Benjamin C. Holding (et al.). Sleep 40 (11)

    Objectives: Insufficient sleep has been associated with impaired recognition of facial emotions. However, previous studies have found inconsistent results, potentially stemming from the type of static picture task used. We therefore examined whether insufficient sleep was associated with decreased emotion recognition ability in two separate studies using a dynamic multimodal task.

    Methods: Study 1 used a cross-sectional design consisting of 291 participants with questionnaire measures assessing sleep duration and self-reported sleep quality for the previous night. Study 2 used an experimental design involving 181 participants where individuals were quasi-randomized into either a sleep-deprivation (N = 90) or a sleep-control (N = 91) condition. All participants from both studies were tested on the same forced-choice multimodal test of emotion recognition to assess the accuracy of emotion categorization.

    Results: Sleep duration, self-reported sleep quality (study 1), and sleep deprivation (study 2) did not predict overall emotion recognition accuracy or speed. Similarly, the responses to each of the twelve emotions tested showed no evidence of impaired recognition ability, apart from one positive association suggesting that greater self-reported sleep quality could predict more accurate recognition of disgust (study 1).

    Conclusions: The studies presented here involve considerably larger samples than previous studies and the results support the null hypotheses. Therefore, we suggest that the ability to accurately categorize the emotions of others is not associated with short-term sleep duration or sleep quality and is resilient to acute periods of insufficient sleep.

  • 2017. Tina Sundelin (et al.). Royal Society Open Science 4 (5)

    The importance of assessing evolutionarily relevant social cues suggests that humans should be sensitive to others' sleep history, as this may indicate something about their health as well as their capacity for social interaction. Recent findings show that acute sleep deprivation and looking tired are related to decreased attractiveness and health, as perceived by others. This suggests that one might also avoid contact with sleep-deprived, or sleepy-looking, individuals, as a strategy to reduce health risk and poor interactions. In this study, 25 participants (14 females, age range 18-47 years) were photographed after 2 days of sleep restriction and after normal sleep, in a balanced design. The photographs were rated by 122 raters (65 females, age range 18-65 years) on how much they would like to socialize with the participants. They also rated participants' attractiveness, health, sleepiness and trustworthiness. The results show that raters were less inclined to socialize with individuals who had gotten insufficient sleep. Furthermore, when sleep-restricted, participants were perceived as less attractive, less healthy and more sleepy. There was no difference in perceived trustworthiness. These findings suggest that naturalistic sleep loss can be detected in a face and that people are less inclined to interact with a sleep-deprived individual.

  • 2017. Bianka Karshikoff, Tina Sundelin, Julie Lasselin. Frontiers in Immunology 8

    Fatigue is a highly disabling symptom in various medical conditions. While inflammation has been suggested as a potential contributor to the development of fatigue, underlying mechanisms remain poorly understood. In this review, we propose that a better assessment of central fatigue, taking into account its multidimensional features, could help elucidate the role and mechanisms of inflammation in fatigue development. A description of the features of central fatigue is provided, and the current evidence describing the association between inflammation and fatigue in various medical conditions is reviewed. Additionally, the effect of inflammation on specific neuronal processes that may be involved in distinct fatigue dimensions is described. We suggest that the multidimensional aspects of fatigue should be assessed in future studies of inflammation-induced fatigue and that this would benefit the development of effective therapeutic interventions.

  • 2016. Sean N. Talamas (et al.). Journal of experimental psychology. General 145 (5), 603-620

    Impression formation is profoundly influenced by facial attractiveness, but the existence of facial cues which affect judgments beyond such an attractiveness halo may be underestimated. Because depression and tiredness adversely affect cognitive capacity, we reasoned that facial cues to mood (mouth curvature) and alertness (eyelid-openness) affect impressions of intellectual capacity. Over 4 studies we investigated the influence of these malleable facial cues on first impressions of intelligence. In Studies 1 and 2 we scrutinize the perceived intelligence and attractiveness ratings of images of 100 adults (aged 18-33) and 90 school-age children (aged 5-17), respectively. Intelligence impression was partially mediated by attractiveness, but independent effects of eyelid-openness and subtle smiling were found that enhanced intelligence ratings independent of attractiveness. In Study 3 we digitally manipulated stimuli to have altered eyelid-openness or mouth curvature and found that each independent manipulation had an influence on perceptions of intelligence. In a final set of stimuli (Study 4) we explored changes in these cues before and after sleep restriction, to examine whether natural variations in these cues according to sleep condition can influence perceptions. In Studies 3 and 4 variations with increased eyelid-openness and mouth curvature were found to relate positively to intelligence ratings. These findings suggest potential overgeneralizations based on subtle facial cues that indicate mood and tiredness, both of which alter cognitive ability. These findings also have important implications for students who are directly influenced by expectations of ability and teachers who may form expectations based on initial perceptions of intelligence.

  • 2015. Tina Sundelin (et al.). Brain, behavior, and immunity 48, 53-56

    An ability to detect subtle signs of sickness in others would be highly beneficial, as it would allow for behaviors that help us avoid contagious pathogens. Recent findings suggest that both animals and humans are able to detect distinctive odor signals of individuals with activated innate immune responses. This study tested whether an innate immune response affects a person's walking speed and whether other people perceive that person as less healthy. 43 subjects watched films of persons who were experiencing experimental immune activation, and rated the walking individuals in the films with respect to health, tiredness, and sadness. Furthermore, the walking speed in the films was analyzed. After LPS injections, participants walked more slowly and were perceived as less healthy and more tired as compared to when injected with placebo. There was also a trend for the subjects to look sadder after LPS injection than after placebo. Furthermore, there were strong associations between walking speed and the appearance of health, tiredness, and sadness. These findings support the notion that walking speed is affected by an activated immune response, and that humans may be able to detect very early signs of sickness in others by merely observing their gait. This ability is likely to aid both a "behavioral immune system", by providing more opportunities for adaptive behaviors such as avoidance, and the anticipatory priming of biochemical immune responses.

Visa alla publikationer av Tina Sundelin vid Stockholms universitet

Senast uppdaterad: 9 januari 2020

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