State shyness enhances recruitment of social processing regions while reducing communication of prefrontal regulatory regions.

State shyness is characterized by a swift and intense emotional response to social stressors, playing a crucial role in shaping the dynamic neural processes in social interactions. However, its underlying neural mechanisms remain unclear. Using a novel shyness-induction paradigm and functional magnetic resonance imaging (fMRI), we investigated brain activation and connectivity patterns associated with state shyness in 41 healthy adults (25 females; Mage = 21.41 ± 2.56). State shyness elicited increased activity in social processing regions, including the bilateral superior temporal, left middle temporal, and medial superior frontal regions. On the network level state shyness decreased connectivity within a regulatory frontal network encompassing dorsomedial prefrontal, anterior cingulate, superior, and inferior frontal systems. No effect on amygdala activation or connectivity was observed. These findings highlight distinct neural correlates of state shyness, emphasizing its reliance on prefrontal and temporal regions for immediate emotion regulation and social cognitive control. Moreover, the results differentiate state shyness from trait shyness, with the latter more closely linked to sustained interactions between the prefrontal cortex and limbic system, especially the amygdala. By elucidating the neural underpinnings of state shyness, this study contributes to a deeper understanding of the situational and transient nature of shy responses in dynamic social contexts.