Highly anxious individuals often show excessive emotional arousal, somatic arousal and characteristics of mental illness. Previous researches have extensively investigated the emotional and cognitive biases of individuals with high anxiety, but overlooked the spontaneous brain activity and functional connections associated with somatic arousal. In this study, we investigated the relationship between the state anxiety and the spontaneous brain activity of the somatosensory cortex in a non-clinical healthy population with state anxiety. Furthermore, we also explored the functional connections of the somatosensory cortex. We found state anxiety was positively correlated with the amplitude of low-frequency fluctuations (ALFF) of somatic related brain regions, including the right postcentral gyrus (somatosensory cortex), and the right precentral gyrus (somatic motor cortex). Furthermore, we found state anxiety was positively correlated with the connections between the postcentral gyrus and the left cerebellum gyrus, whereas state anxiety was negatively correlated with the connectivity between the postcentral gyrus and brain regions including the left inferior frontal cortex and left medial superior frontal cortex. These results revealed the association between the anxious individuals’ body-loop and state anxiety in healthy population, which revealed the importance of somatic brain regions in anxiety symptoms and provided a new perspective on anxiety for further study.

Prominent theories propose that interoception modulates our behavioral and emotional responses involving decision-making and emotion regulation. Are the regions implicated in interoception also spatially related to and possibly nested within the networks of decision making and emotion regulation? Addressing this question, we performed three meta-analyses of functional magnetic resonance imaging studies to identify the regions that are commonly activated by the three domains using activation likelihood estimation (ALE). Additionally, we assessed the coactivation pattern of identified common regions using meta-analytic connectivity modeling (MACM). The results showed major overlaps of interoception with both decision making and emotion regulation in specifically the right dorsal anterior insula. The pairwise contrast analyses confirmed this finding and revealed conjunction-based activities in decision making and emotion regulation in the dorsal anterior cingulate cortex (dACC). MACM based on the identified insula revealed a widespread convergent coactivation pattern with the left anterior insula, dACC, and bilateral thalamus which, together, constitute the salience network. Among these co-activated regions, bilateral insula and the dACC were shared among all three domains. These results suggest that the regions mediating interoception including intero-exteroceptive integration and salience attribution are contained and thus spatially nested within the more extensive networks recruited during decision making and emotion regulation.

Individuals with high trait anxiety form a non-clinical group with a predisposition for an anxiety-related bias in emotional and cognitive processing that is considered by some to be a prerequisite for psychiatric disorders. Anxious individuals tend to experience more worry under uncertainty and processing uncertain information is an important, but often overlooked factor in anxiety. So, we decided to explore the brain correlates of processing uncertain information in individuals with high trait anxiety using the learn-test paradigm. Behaviorally, the percentages on memory test and the likelihood ratios of identifying novel stimuli under uncertainty were similar to the certain fear condition, but different from the certain neutral condition. The brain results showed that the visual cortex, bilateral fusiform gyrus and right parahippocampal gyrus were active during the processing of uncertain cues. Moreover, we found that trait anxiety was positively correlated with the BOLD signal of the right parahippocampal gyrus during the processing of uncertain cues. No significant results were found in the amygdala during uncertain cue processing. These results suggest that memory retrieval is associated with uncertain cue processing, which is underpinned by over-activation of the right parahippocampal gyrus, in individuals with high trait anxiety.