Low-grade inflammation decreases emotion recognition – Evidence from the vaccination model of inflammation

• Published in: Brain, behavior, and immunity behavior, and immunity, 2018-10, Vol.73, p.216-221
• Main Authors: Balter, Leonie J.T., Hulsken, Sasha, Aldred, Sarah, Drayson, Mark T., Higgs, Suzanne, Veldhuijzen van Zanten, Jet J.C.S., Raymond, Jane E., Bosch, Jos A.
• Format: Article
• Language: English
• Subjects: Adult; Affective Symptoms - pathology; Cognition - physiology; Cross-Over Studies; Cytokines; Double-Blind Method; Emotional Intelligence - physiology; Emotions - physiology; Humans; Inflammation; Inflammation - metabolism; Inflammation - pathology; Interleukin-6 - analysis; Interleukin-6 - blood; Interpersonal Relations; Male; Psychoneuroimmunology; Reading the mind in the eyes; Sickness behavior; Social cognition; Theory of mind; Theory of Mind - physiology; Typhoid vaccination; Typhoid-Paratyphoid Vaccines; Vaccination
• ISSN: 0889-1591; 1090-2139
• DOI: 10.1016/j.bbi.2018.05.006

•Typhoid vaccination elicited low-grade inflammation without sickness symptoms.•Inflammation resulted in lower ability to interpret the mental state of someone else.•Inflammation may contribute to social-cognitive deficits in inflammatory states. The ability to adequately interpret the mental state of another person is key to complex human social interaction. Recent evidence suggests that this ability, considered a hallmark of ‘theory of mind’ (ToM), becomes impaired by inflammation. However, extant supportive empirical evidence is based on experiments that induce not only inflammation but also induce discomfort and sickness, factors that could also account for temporary social impairment. Hence, an experimental inflammation manipulation was applied that avoided this confound, isolating effects of inflammation and social interaction. Forty healthy male participants (mean age = 25, SD = 5 years) participated in this double-blind placebo-controlled crossover trial. Inflammation was induced using Salmonella Typhi vaccination (0.025 mg; Typhim Vi, Sanofi Pasteur, UK); saline-injection was used as a control. About 6 h 30 m after injection in each condition, participants completed the Reading the Mind in the Eyes Test (RMET), a validated test for assessing how well the mental states of others can be inferred through observation of the eyes region of the face. Vaccination induced systemic inflammation, elevating IL-6 by +419% (p  .21). Importantly, compared to placebo, vaccination significantly reduced RMET accuracy (p