Unveiling the Neural Correlates of Incidental Memory: a Meta-analysis of fMRI Studies

A significant body of research sought to understand the mechanisms underlying memory formation and retrieval. Even when focusing exclusively on episodic memory, several subcategories emerge, such as explicit, implicit, and autobiographical memory. In this study, we utilized Activation Likelihood Estimation (ALE) to perform an fMRI meta-analysis to identify the neural bases of incidental memory. Results showed a network involving the inferior frontal gyrus (IFG), the precuneus, and the inferior occipital gyrus. When focusing exclusively on the encoding phase of incidental memory tasks, the results revealed a specific cluster in the IFG, confirming the findings from the primary meta-analysis. To further investigate the functional connectivity of this key node in incidental memory, we conducted a Meta-Analytic Connectivity Modelling (MACM) analysis on the identified cluster, highlighting a network of activation overlapping with the salience and, partially, with the frontoparietal control network. These findings suggest that the inferior frontal gyrus has a key role in the incidental encoding of episodic information, either via its involvement in verbal processing or driving attentive processing of potentially salient stimuli.