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  • Research in ASD and typical populations has highlighted a

    2018-11-15

    Research in ASD and typical populations has highlighted a link between temporal lobe activation and social behavioral profiles. Social responsiveness (as measured by the SRS) has been found to be negatively correlated with right pSTS responses to social stimuli in children with ASD (Kaiser et al., 2010). Another measure of autistic traits, the autism quotient (AQ; Baron-Cohen et al., 2001), predicts variability in both structure and function of the pSTS in healthy adults (von dem Hagen et al., 2011) and correlates with pSTS responses to social touch in healthy adults (Voos et al., 2013). In the current study, 15 children with ASD had parent-reported measures of social responsiveness (SRS). A post hoc Pearson correlation revealed that activation in the trait-defined right aTPJ/pSTS showed a significant negative correlation with SRS score, as predicted (r(13)=−0.7, p<0.05, two-tailed; Fig. 2). This means that within our ASD sample, increased impairment in social responsiveness was related to decreased activation in right aTPJ/pSTS during social exclusion compared to fair play. This is consistent with the finding that compared to TD youth with no social impairment, children with ASD showed significantly less activation in right aTPJ/pSTS. We will expound upon the second explanation, that the UAS share some neural abnormalities with their autistic counterparts, however are able to maintain normal levels of social functioning. This explanation is supported by our careful characterization of the UAS group with the goal of excluding siblings displaying the broad autism phenotype. The conclusion that the unaffected siblings display normal social functioning is also supported by our failure to differentiate TD and UAS based on dub ubiquitin activation in many regions repeatedly implicated in typical processing of social exclusion. The regions identified in the within-group comparison of Social Exclusion>Fair Play in UAS were strikingly similar to activation patterns found in TD youth. One region of specific interest where TD and UAS groups did not diverge was the ACC. Both groups showed robust activation in ACC, an area found to be active in many tasks eliciting the experience of social rejection (Bolling et al., 2011a,c; Masten et al., 2009; Moor et al., 2012; Sebastian et al., 2011). Importantly, two independent investigations have reported hypoactivation of this region during social exclusion in youth with ASD (Bolling et al., 2011b; Masten et al., 2011). With respect to the ACC, the UAS demonstrated typical neural responses to social rejection. Posterior temporal lobe activation to social exclusion is often undiscussed, in favor of prefrontal and midline emotion-related neural circuitry such as the ACC. Despite the intriguing nature of temporal lobe activation in ASD symptomatology, caution must be taken when interpreting the potential psychological correlates of abnormal activation in aTPJ/pSTS identified in the current study. The region identified as aTPJ/pSTS is somewhat anterior to typical TPJ coordinates reported in social cognition and mentalization research (TPJ: (50, −55, 25), pSTS: (50, −55, 10); Van Overwalle and Baetens, 2009). The absolute maximum of our reported aTPJ/pSTS cluster is questionably representative of our anatomical label. However, the location of the next-most significant local maximum within the cluster better reflects this label. Multiple studies of the TPJ have found that the region serves both social and attentional functions (for reviews see Carter and Huettel, 2013; Decety and Lamm, 2007). However, within the TPJ, attention/reorienting processes tend to lie more anterior than social processes, with the former dub ubiquitin being centralized near the supramarginal gyrus and the latter being located near the angular gyrus. Thus, with the finding that our group differences in aTPJ/pSTS activation to social exclusion lie anterior to typical TPJ coordinates, it is possible that this activation is better characterized by attentional reorienting processes occurring during the Cyberball game. It has been hypothesized that the TPJ serves a role in contextual updating, a relatively late process in response to attentional cues (Geng and Vossel, 2013). This hypothesis predicts that activation in TPJ is increased in situations of expectancy violation, because events that violate one\'s predictions lead to shifts in mental context models. With this hypothesis in mind, it is possible that aTPJ/pSTS activation to social exclusion in the current study reflects a contextual updating process in response to a violation of the expectancy of social inclusion. Thus, hypoactivation in UAS and ASD groups may represent atypical social expectancies within these groups, or a deficit in contextual updating in response to experiencing unpredicted exclusion. It is of note that there still exists uncertainty over whether different cognitive functions activating the TPJ (e.g. social vs. attentional) represent distinct sub-regional functions in this brain area, or a unifying function that underlies the common cognitive domains subserved by the region (Lee and McCarthy, 2014).