Seeing more than schemas: the vmPFC represents imagery-rich mental scenarios

Mental imagery varies dramatically across individuals, from vivid scene construction to the complete absence of visual experience, as seen in aphantasia. While the ventromedial prefrontal cortex (vmPFC) is traditionally associated with abstract, schematic representations, emerging theories suggest it also contributes to constructing perceptually rich, temporally extended mental scenarios. To test this, we developed a 7T fMRI experiment that varied imagery demands across conditions: participants memorized richly detailed scenarios, more constrained stationary objects, and semantic definitions for three abstract German words (e.g., hope). During scanning and eye-tracking, the same cue word was presented on every trial, but participants vividly re-engaged with one of three learned representations (scenario construction, object construction, or semantic definitions). Using the same word across conditions enabled us to disentangle perceptual richness from semantic scaffolding and to test directly whether vmPFC represents imagery-rich scenarios rather than functioning solely as a conceptual coordinator. Univariate analyses revealed increased activation in vmPFC, medial temporal regions, and occipital cortex during scenario construction. Multivoxel pattern analysis (MVPA) showed that the vmPFC was the only region examined in which classifier accuracy for scenarios exceeded that of object construction and semantic definitions, supporting its role in representing imagery-rich details rather than solely abstract schemas. Eye movement patterns further distinguished conditions, reflecting differences in constructive processes. These findings advance models of vmPFC function, highlighting its contribution to integrating perceptual richness with conceptual meaning in temporally extended mental scenarios.