Abstract
Individual differences in how the brain responds to novelty are present from infancy. A common method of studying novelty processing is through event-related potentials (ERPs). While ERPs possess millisecond precision, spatial resolution remains poor, especially in infancy. This study aimed to balance spatial and temporal precision by combining ERP data with functional magnetic resonance imaging (fMRI) data. Twenty-nine infants (15 female) underwent resting-state fMRI (M(age) = 4.73 months) and electroencephalography (EEG) during a three-stimulus auditory oddball task (M(age) = 5.19 months). The mismatch response (MMR) and P3 were computed from ERP data, and resting-state functional connectivity (rs-FC) was computed from fMRI data. We first source localized the MMR and P3 responses to five regions-of-interest (ROIs), based on prior literature. We then performed network-level enrichment analyses to identify associations between rs-FC and MMR and P3, at each of the five ROIs. In line with prior work, source-localized EEG analyses implicated the bilateral auditory cortices, posterior cingulate cortex, and superior parietal cortex in the generation of MMR and P3 responses. The MMR and P3 related to functional connectivity within the somatomotor network as well as between the somatomotor and the dorsal and ventral attention networks (DAN/VAN). This was especially true for novelty response ERPs recorded at superior parietal lobule, known for its implications in initial reorienting to novel stimuli. The DAN, known for its implication in initial reorienting to support novelty detection, was implicated for the MMR. In contrast, the VAN, known for its support of later-stage, complex adjustments in attention, related to the later P3. This work further solidifies our understanding of the underlying networks implicated in the development of immediate responses to stimuli. Altered configurations of such networks may increase the risk for heightened sensitivity to novelty in certain individuals, which could have behavioral and clinical significance. (PsycInfo Database Record (c) 2025 APA, all rights reserved).