Spatiotemporal dynamics of frontoparietal networks in semantic intuitive decision-making

According to Bowers' continuity model, semantic intuitive decision-making involves a gradual transition from an implicit guiding stage to an explicit integration stage. Using functional near-infrared spectroscopy (fNIRS) in 45 participants performing a word triad association task, we investigated the localized hemodynamic activity, functional connectivity architecture, and the neural dynamics distinguishing the guiding and integration stages of semantic intuition. Imaging results revealed a spatiotemporal dissociation between the two stages: the guiding stage predominantly recruited superior/middle frontal and sensorimotor regions, whereas the integration stage engaged distinct frontoparietal circuits. Temporally, semantic encoding during the guiding stage progressed from the left middle frontal gyrus to the medial superior frontal gyrus, while integration-stage processing selectively involved right frontoparietal networks. These findings provide a neurobiological framework for understanding the distinct neural architectures underlying the two stages of semantic intuitive decision-making and offer a basis for investigating individual differences in non-deliberative cognitive processes.