A third limitation is that

A third limitation is that participant characteristics including sex, stage of pubertal development, and race were only minimally considered. Beyond the comparison of adults and adolescents, we did not have a sufficiently large number of participants to isolate influences of these and other potentially important variables on the anxiety-brain function relationship. Mounting evidence suggests sex (Guyer et al., 2009, 2012, 2014b; Lee et al., 2014) and pubertal stage (Jankowski et al., 2014; Klapwijk et al., 2013) based differences in matrix metalloproteinase and behavioral responses to social stimuli. We had insufficient power to test for interactions among sex, pubertal development, social anxiety, and age group. However, we did conduct two secondary analyses (see Supplementary Material), one restricted to female participants, and another that closely matched adult and adolescent groups based on sex, age, and pubertal development. For both of these analyses, results showed similar patterns as in the primary analyses, despite their markedly smaller sample size. This suggests that while sex and pubertal development play some role in influencing brain response in the current study, our results for social anxiety and age group remain when controlling for these factors. Finally, brain responses engaged by social exclusion (Masten et al., 2011), emotion processing (Lieberman et al., 2005), and trust-based evaluations (Stanley et al., 2012) also vary depending on the congruency of race with participants. These differences are influenced by early life exposure people of other races (Telzer et al., 2013a), and vary based on development (Telzer et al., 2013b). Given that the majority of participants in this study were White, non-Hispanic or Latino, we were unable to test the effects of race on brain function. Future studies should be designed specifically to disentangle the effects of sex, race, pubertal phase, and severity of anxiety symptoms on brain function during social processing.
Conclusion
Conflict of interest
Acknowledgement This research (NCT# 00018057; Protocol ID 01-M-0192) was supported by the NIMH intramural research program.
Introduction The intraparietal sulcus (IPS) is located along the dorsal visual pathway and is a key node in the network underlying spatial attention (Astafiev et al., 2003; Corbetta et al., 2000; Goodale and Milner, 1992; Silver and Kastner, 2009). This functionally heterogeneous brain region has also been implicated in multisensory attention (Anderson et al., 2010), working memory (Champod and Petrides, 2007; Pessoa et al., 2002), and numerical cognition (Cantlon and Li, 2013; Dehaene et al., 2003; Pinel et al., 2001; Rosenberg-Lee et al., 2011). The IPS is a core node of the dorsal attention (Power et al., 2011) or task-positive network (Fox et al., 2005; Toro et al., 2008), which includes putative human frontal eye fields (hFEF) and supplementary motor area (hSMA) as well as dorsolateral prefrontal cortex (DLPFC) and occipito-temporal regions (near human middle temporal (MT)+). The IPS can be divided into a set of regions spanning the anterior-to-posterior axis, on the basis of phase reversals in topographic organization, similar to retinotopic visual cortex (Sereno et al., 2001). These regions show differences in functional responses across tasks (Bray et al., 2013a; Sheremata et al., 2010; Silver and Kastner, 2009; Swisher et al., 2007; Szczepanski et al., 2013), and differential white matter structural connectivity to visual regions and parts of the dorsal attention network (Bray et al., 2013b; Greenberg et al., 2012; Szczepanski et al., 2013). In these studies, structural connectivity is defined using probabilistic tractography to determine the likelihood that two regions are joined by a direct white matter pathway. With regards to the IPS, posterior regions show preferential connectivity with dorsal and ventral visual regions (Bray et al., 2013b; Greenberg et al., 2012), while anterior regions show more probable connections to prefrontal and pre-motor regions (Bray et al., 2013b; Mars et al., 2011; Szczepanski et al., 2013). Lesion studies (Vandenberghe et al., 2012) and task activation and connectivity studies (Hutchinson et al., 2015) further support functional sub-divisions along the IPS.