Age-Dependent Signature of Serum Inflammatory Cytokines in Healthy Children and Young Adults.

The study of sensitive and specific biomarkers, such as blood inflammatory cytokines, could provide an answer to the challenges faced in the differential diagnosis of patients with systemic inflammation. Limited data exist on the impact of age on serum levels of inflammatory cytokines. We collected serum samples of 42 healthy children and young adults (1 month to 21 years). Serum levels of interleukin 1 receptor antagonist (IL-1Ra), IL-1ß, IL-6, IL-18, tumor necrosis factor-alpha (TNF-α), CXCL9, and CXCL10 were measured. Data were analyzed for three different age groups (<6, 6-17, and 18-21 years). IL-18, TNF-α, and CXCL9 values varied significantly according to age group. Median values of IL-18 and TNF-α decline with age, whereas CXCL9 and CXCL10 are lowest at 6-17 years. IL-1Ra is stable among age groups. In the majority of cases, IL-1ß and IL-6 are not measurable above the lower limit of quantification. A scoping literature review revealed highly variable data on IL-1Ra, IL-18, TNF-α, and CXCL10. For CXCL9, pediatric reference data are scarce. In conclusion, we report an age-dependent signature of multiple inflammatory cytokines measured in the serum of healthy children and young adults, suggesting the need to use age-specific reference values in future pediatric studies.

Neural correlates of own name and own face processing in neurotypical adults scoring low versus high on symptomatology of autism spectrum disorder.

Previous event-related potential (ERP) research showed reduced self-referential processing in autism spectrum disorder (ASD). As different self-related stimuli were studied in isolation, it is unclear whether findings can be ascribed to a common underlying mechanism. Further, it is unknown whether altered self-referential processing is also evident in neurotypicals scoring high on ASD symptomatology. We compared ERPs in response to one's own name and face (versus other names/faces) between neurotypical adults scoring high versus low on ASD symptomatology. Conform previous research, the parietal P3 was enhanced, both for own name and face, indicating a self-referential effect. The N250 was only enhanced for one's own face. However, the self-referential parietal P3 effect did not correlate between the names and faces conditions, arguing against a common underlying mechanism. No group effects appeared, neither for names nor faces, suggesting that reduced self-referential processing is not a dimensional ASD feature in the neurotypical population.

Measuring spontaneous mentalizing with a ball detection task: putting the attention-check hypothesis by Phillips and colleagues (2015) to the test.

Theory of Mind (ToM) or mentalizing refers to the ability to attribute mental states (such as desires, beliefs or intentions) to oneself or others. ToM has been argued to operate in an explicit and an implicit or a spontaneous way. In their influential paper, Kovács et al. (Science 330:1830-1834, 2010) introduced an adapted false belief task-a ball detection task-for the measurement of spontaneous ToM. Since then, several studies have successfully used versions of this paradigm to investigate spontaneous ToM. This paradigm has, however, been criticized by Phillips et al. (Psychol Sci 26(9):1353-1367, 2015), who argue that the effects are fully explained by timing artifacts in the paradigm, namely differences in timing of the attention check. The main objective of the current study is to test this attention-check hypothesis. An additional aim was to relate the findings to autism spectrum disorder (ASD) symptomatology in our neurotypical sample, as ASD has been linked to deficits in spontaneous mentalizing. We applied an adjusted version of the paradigm in which the timings for all conditions are equalized, ruling out any potential timing confounds. We found significant main effects of own and agent beliefs on reaction times. Additionally, we found a significant 'ToM-effect': When participants believe the ball is absent, they detect the ball faster if the agent believes the ball would be present rather than absent, which refers to the original effect in the paper of Kovács et al. (2010), taken as evidence for spontaneous ToM and which was contested by Phillips et al. (2015). Our findings cannot be explained by the attention-check hypothesis. Effects could not be associated with ASD symptoms in our neurotypical sample, warranting further investigation on the link between spontaneous mentalizing and ASD.

To make a molehill out of a mountain: An ERP-study on cognitive reappraisal of negative pictures in children with and without ADHD.

OBJECTIVE: We investigated cognitive reappraisal in children with ADHD by means of the late positive potential (LPP) and self-report ratings. We expected diminished LPP modulation following reappraisal and lower self-report scores in children with ADHD. METHODS: Eighteen children with ADHD and 24 typically developing (TD) children (8-12years) performed a cognitive reappraisal task, while EEG was recorded, and filled out a questionnaire on cognitive reappraisal. RESULTS: Despite the lack of main reappraisal effects on LPP, the LPP was less positively modulated during reappraisal in ADHD compared to TD children. CONCLUSIONS: Children with ADHD reported less use of reappraisal and could be distinguished from TD children based on LPP modulation. However the lack of main effects of reappraisal on LPP in both groups hinders clear interpretation of this finding and questions the suitability of LPP modulation within the current paradigm as a neural index of reappraisal in children 8-12years old, and warrants further research on the inter-individual variability and sensitivity of LPP modulation as a neural index of emotion regulation in children. SIGNIFICANCE: This is the first study investigating the LPP during cognitive reappraisal in children with ADHD.