Semantic Dimensions Support the Cortical Representation of Object Memorability

Recent work in vision sciences contends that objects carry an intrinsic property, memorability, that describes the likelihood that an object can be successfully encoded and later retrieved from memory. It has been shown that object memorability is supported by semantic information, but the neural correlates involved are largely unexplored. The present study explores these premises and asks whether neural correlates of object memorability can be accounted for by semantic dimensions. To investigate these questions, we combine three datasets: (1) feature norms for a database of ~1000 natural object images, (2) normative conceptual and perceptual memory data for those objects, and (3) neuroimaging data from an fMRI study collected using a subset (n=360) of those objects. We found that object-wise memorability elicits consistent brain activation across participants in key mnemonic regions (e.g., hippocampus and rhinal cortex), and that a substantial portion of the variance in this brain activity is mediated by the semantic factors describing these images. Regions with the strongest mediation effects are associated with sensory, motor, and visual processes, suggesting that the relationship between memorability and semantics may align with a sensory-functional account of the representation of concepts in the brain.