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The amygdala plays a critical role in emotion. Its functional coupling with the hippocampus and ventromedial prefrontal cortex extending to a portion of the anterior cingulate cortex (ACC) is implicated in anxiogenesis and hypothalamic-pituitary-adrenal (HPA) system regulation. However, it remains unclear how amygdala-centred functional connectivity (FC) affects anxiety and cortisol concentrations in everyday life. Here, we investigate the relationship between daily cortisol concentrations (dCOR) and amygdala-centred FC during emotional processing in forty-one healthy humans. FC analyses revealed that higher dCOR predicted strengthened amygdala-centred FC with the hippocampus and cerebellum, but inhibited FC with the supramarginal gyrus and a perigenual part of the ACC (pgACC) when processing fearful faces (vs. neutral faces). Notably, the strength of amygdala-hippocampus FC mediated the positive relationship between cortisol and anxiety, specifically when the effect of amygdala-pgACC FC, a presumptive neural indicator of emotional control, was taken into account. Individuals with diminished connectivity between the amygdala and pgACC during fear-related processing might be more vulnerable to anxiogenesis as it pertains to greater circulating cortisol levels in everyday life. Individual functional patterns of amygdala-hippocampal-pgACC connectivity might provide a key to understand the complicate link between cortisol and anxiety-related behaviors.

The pulvinar is important in selective attention, particularly to visual stimuli under the focus of attention. However, the pulvinar is assumed to process emotional stimuli even outside the focus of attention, because of its tight connection with the amygdala. We therefore investigated how unattended emotional stimuli affect the pulvinar and its effective connectivity (EC) while considering individual differences in selective attention. fMRI in 41 healthy human subjects revealed that the amygdala, but not the pulvinar, more strongly responded to unattended fearful faces than to unattended neutral faces (UF > UN), although we observed greater EC from the pulvinar to the amygdala. Interestingly, individuals with biased attention toward threat (i.e., attentional bias) showed significantly increased activity (UF > UN) and reduced grey matter volume in the pulvinar. These individuals also exhibited stronger EC from the pulvinar to the attention-related frontoparietal network (FPN), whereas individuals with greater attentional control showed more enhanced EC from the pulvinar to the amygdala, but not the FPN (UF > UN). The pulvinar may filter unattended emotional stimuli whose sensitivity depends on individual threat-related attentional bias. The connectivity patterns of the pulvinar may thus be determined based on individual differences in threat-related attentional bias and attentional control.