Humans observe various peoples' social suffering throughout their lives, but it is unknown whether the same brain mechanisms respond to people we are close to and strangers' social suffering. To address this question, we had participant's complete functional magnetic resonance imaging (fMRI) while observing a friend and stranger experience social exclusion. Observing a friend's exclusion activated affective pain regions associated with the direct (i.e. firsthand) experience of exclusion [dorsal anterior cingulate cortex (dACC) and insula], and this activation correlated with self-reported self-other overlap with the friend. Alternatively, observing a stranger's exclusion activated regions associated with thinking about the traits, mental states and intentions of others ['mentalizing'; dorsal medial prefrontal cortex (DMPFC), precuneus, and temporal pole]. Comparing activation from observing friend's vs stranger's exclusion showed increased activation in brain regions associated with the firsthand experience of exclusion (dACC and anterior insula) and with thinking about the self [medial prefrontal cortex (MPFC)]. Finally, functional connectivity analyses demonstrated that MPFC and affective pain regions activated in concert during empathy for friends, but not strangers. These results suggest empathy for friends' social suffering relies on emotion sharing and self-processing mechanisms, whereas empathy for strangers' social suffering may rely more heavily on mentalizing systems.

Western cultures encourage self-construals independent of social contexts, whereas East Asian cultures foster interdependent self-construals that rely on how others perceive the self. How are culturally specific self-construals mediated by the human brain? Using functional magnetic resonance imaging, we monitored neural responses from adults in East Asian (Chinese) and Western (Danish) cultural contexts during judgments of social, mental and physical attributes of themselves and public figures to assess cultural influences on self-referential processing of personal attributes in different dimensions. We found that judgments of self vs a public figure elicited greater activation in the medial prefrontal cortex (mPFC) in Danish than in Chinese participants regardless of attribute dimensions for judgments. However, self-judgments of social attributes induced greater activity in the temporoparietal junction (TPJ) in Chinese than in Danish participants. Moreover, the group difference in TPJ activity was mediated by a measure of a cultural value (i.e. interdependence of self-construal). Our findings suggest that individuals in different sociocultural contexts may learn and/or adopt distinct strategies for self-reflection by changing the weight of the mPFC and TPJ in the social brain network.

Many biologically active macrocycles contain a C–C double bond through which various other derivatives are prepared; the stereochemical identity of the alkene or the resulting moieties can be critical to the beneficial properties of such molecules. Catalytic ring-closing metathesis (RCM) is a widely employed method for the synthesis of large unsaturated rings;1,2 however, cyclizations often proceed without control of alkene stereochemistry.2 Such shortcoming is particularly costly with complex molecules when cyclization is performed after a long sequence of transformations.2 Here, we outline a reliable, practical and general approach for efficient and highly stereoselective synthesis of macrocyclic alkenes by catalytic RCM; transformations deliver up to 97% Z selectivity due to control induced by a tungsten-based alkylidene. Utility is demonstrated by stereoselective preparation of anti-cancer epothilone C [Ref. 3–5] and anti-microbial nakadomarin A [Ref. 6], previously reported syntheses of which have been marred by late-stage non-selective RCM.7–15 The tungsten alkylidene can be manipulated in air, promoting reactions carried out in a fume hood to deliver products in useful yields and high Z selectivity. As a result of efficient RCM and re-incorporation of side products into the catalytic cycle with minimal alkene isomerization, desired cyclizations proceed in preference to alternative pathways even under relatively high concentration (0.1 molar).