Association of Genetic Variation in the Promoter Region of OXTR with Differences in Social Affective Neural Processing

Evidence supports the involvement of oxytocin in social behavior. The oxytocin receptor gene (OXTR) has been associated with differences in social brain function and risk for autism. Motivated by recent work, we investigated the effect of variation in the common functional rs2268498 T/C polymorphism in the promoter region of OXTR on neural responses to fear expressions. 46 healthy subjects were divided into genotype groups of C carriers (n = 32) and TT ho-mozygous (n = 14) and neural activity was measured during the recognition of fear and neutral expressions. Results showed that during the recognition of fear expressions, the TT genotype group exhibited increased responding in the inferior occipital gyrus, considered important for face processing, compared to carriers of the C allele (P < 0.005;cluster corrected for whole brain), an effect not found for neutral faces. These results indicate the impact of this OXTR genetic variant on individual differences in social affective neural processing.

Neuroimaging the effects of smartphone(over-)use on brain function and structure-a review on the current state of MRI-based findings and a roadmap for future research

The smartphone represents a transformative device that dramatically changed our daily lives,including how we communicate,work,entertain ourselves,and navigate through unknown territory.Given its ubiquitous availability and impact on nearly every aspect of our lives,debates on the potential impact of smartphone(over-)use on the brain and whether smartphone use can be“addictive”have increased over the last years.Several studies have used magnetic resonance imaging to characterize associations between individual differences in excessive smartphone use and variations in brain structure or function.Therefore,it is an opportune time to summarize and critically reflect on the available studies.Following this overview,we present a roadmap for future research to improve our understanding of how excessive smartphone use can affect the brain,mental health,and cognitive and affective functions.

Associations between levels of Internet Gaming Disorder symptoms and striatal morphology–replication and associations with social anxiety

Background:Brain structural alterations of the striatum have been frequently observed in internet gaming disorder(IGD);however,the replicability of the results and the associations with social-affective dysregulations such as social anxiety remain to be determined.Methods:The present study combined a dimensional neuroimaging approach with both voxel-wise and data-driven multivariate approaches to(i)replicate our previous results on a negative association between IGD symptom load(assessed by the Internet Gaming Disorder Scale-Short Form)and striatal volume,(ii)extend these findings to female individuals,and(iii)employ multivariate and mediation models to determine common brain structural representations of IGD and social anxiety(assessed by the Liebowitz Social Anxiety Scale).Results:In line with the original study,the voxel-wise analyses revealed a negative association between IGD and volumes of the bilateral caudate.Going beyond the earlier study investigating only male participants,the present study demonstrates that the association in the right caudate was comparable in both the male and the female subsamples.Further examination using themultivariate approach revealed regionally different associations between IGD and social anxiety with striatal density representations in the dorsal striatum(caudate)and ventral striatum(nucleus accumbens).Higher levels of IGD were associated with higher social anxiety and the association was critically mediated by the multivariate neurostructural density variations of the striatum.Conclusions:Altered striatal volumes may represent a replicable and generalizable marker of IGD symptoms.However,exploratory multivariate analyses revealed more complex and regional specific associations between striatal density and IGD as well as social anxiety symptoms.Variations in both tendencies may share common structural brain representations,which mediate the association between increased IGD and social anxiety.