Neural substrates of multidimensional psychological characteristics of remembering episodes with autobiographical significance

Autobiographic remembering often involves types of constructive processes for psychological experiences and hypothetical scenarios of past events. Previous psychological research revealed a range of phenomenological and functional characteristics associated with recalls of episodes with high autobiographical significance. However, neural bases of such psychological characteristics and their association with memory construction processes remain unclear. In this functional magnetic resonance imaging study, we collected autobiographical episodes from 28 young adults and their extensive metrics of phenomenological and functional characteristics related to autobiographical significance. We then sought to identify neural correlates of the psychological characteristics by measuring brain activity while participants recalled specified episodes as accurately as possible or in counterfactual simulation. Multiple-regression analysis using latent factors of psychological characteristics revealed that a factor representing autobiographical significance was associated with activation in the posterior medial memory system, including the angular cortex, precuneus, and posterior cingulate cortex, during counterfactual simulation. Furthermore, representation similarity analysis using patterns of factor scores revealed significant clusters in the posterior medial system and parts of cerebellar parcels, mainly during counterfactual simulation. These findings indicate that multidimensional psychological characteristics of episodes with autobiographical significance are associated with hypothetical constructive processes in the cortical posterior medial system and cerebellum.