Intrinsic Brain Networks Underlying the Experience and Expression of Subclinical Anxiety
Anxiety encompasses behavioral, physiological, and subjective components that do not always align, yet it remains unclear whether these dimensions are supported by distinct intrinsic brain networks. Drawing on the two-system framework, we examined whether resting-state functional connectivity (rsFC) differentiates these components in subclinical anxiety. Forty-seven young adults with varying levels of subclinical anxiety completed a threat anticipation task to assess anxiety-modulated behavioral responses (reaction time) and physiological arousal (skin conductance), alongside the NIH Fear-Affect self-report measure of anxiety severity. These measures were then related to rsFC using independent component analysis. Higher levels of subclinical anxiety were associated with faster responses during temporally uncertain threat, consistent with escape-like behavior, whereas no relationship emerged between subclinical anxiety and physiological arousal. At the neural level, three distinct connectivity patterns remained significant after sequential false discovery rate correction. Anxiety-modulated behavioral responses were associated with stronger connectivity between the default mode network and regions in the visual cortex and paracingulate gyrus. Physiological modulation by subclinical anxiety was linked to connectivity between the salience network and the visual cortex. In contrast, subjective anxiety was associated with connectivity between the cerebellar network and regions in the frontal, parietal, and visual cortices. Together, these findings suggest that the behavioral, physiological, and subjective dimensions of subclinical anxiety are supported by functionally and spatially dissociable intrinsic brain networks. These results extend previous task-based findings to resting-state connectivity and provide new insights into the intrinsic neural architecture of subclinical anxiety.