The Neural Blueprint of Novelty: A Meta-Analytic Dissection of Active and Passive Novelty Processing Networks.

BACKGROUND: Detecting novel environmental events is a fundamental survival mechanism, enabling organisms to identify and respond to salient changes. This function can operate in at least two broad modes, differing in task demands: active and passive novelty processing. Active processing involves explicitly recognizing novel or deviant stimuli and engaging goal-directed, top-down attentional control and memory-related systems. In contrast, passive processing is driven primarily by bottom-up attentional reorienting and does not necessarily require an explicit response or conscious evaluation. The present study asked whether these two modes recruit a shared neural architecture across task demands.

METHODS: We conducted a coordinate-based meta-analysis using Activation Likelihood Estimation (ALE) across fMRI studies of active and passive novelty processing. Conjunction and subtraction analyses were performed on the resulting ALE maps to identify common and distinct neural substrates associated with each mode of novelty processing.

RESULTS: The conjunction analysis revealed a core novelty-responsive network encompassing the bilateral medial temporal lobes (MTLs), inferior frontal gyrus (IFG), and medial frontal regions. Subtraction analyses further identified task-dependent specializations: studies of active novelty processing showed greater spatial convergence in the left precentral gyrus, left IFG, right MTL, and medial frontal areas, whereas studies of passive processing showed greater convergence in the left superior temporal gyrus, bilateral MTL, and right IFG.

CONCLUSION: These findings suggest that active and passive conditions share a common novelty-responsive network but differentially weight its components, reflecting distinct cognitive and attentional demands imposed by the explicit versus incidental processing of novel events.