Longitudinal changes in infant attention-related brain networks and fearful temperament.

Anxiety disorders are hypothesized to stem in part from altered development of attention-related brain networks. These networks, including the dorsal attention network (DAN), frontal parietal network (FPN), salience network (SN), and default mode network (DMN), are crucial for regulating attention to salient environmental cues. Altered resting-state functional connectivity (rsFC) among these networks in the first months of life relates to fearful temperament, a risk marker for anxiety. Nevertheless, it remains unclear how these networks develop beyond these initial months, particularly in fearful infants. This study characterizes the development of attention-related brain networks over the first two years of life and identifies rsFC changes associated with fearful temperament. Using data from the Baby Connectome Project (from 180 infants across 396 sessions), we analyzed rsFC among the DMN, SN, DAN, and FPN. We examined age-related changes in rsFC across these networks and their relations with fearful temperament at age 2. Results demonstrated age-related decreases in rsFC in DAN - FPN and DMN - SN. Less decrease in DAN - FPN rsFC over time related to greater fear at age 2. This pattern manifested in analyses relating longitudinal trajectories of rsFC and fearful temperament across all available timepoints. Low initial DAN - SN rsFC related to increasing fearfulness over time. This study provides novel insights into the neurodevelopmental origins of fearful temperament.