Neural representation of visual concepts in people born blind.

How do we represent information without sensory features? How are abstract concepts like "freedom", devoid of external perceptible referents, represented in the brain? Here, to address the role of sensory information in the neural representation of concepts, we used fMRI to investigate how people born blind process concepts whose referents are imperceptible to them because of their visual nature ("rainbow", "red"). Activity for these concepts was compared to that of sensorially-perceptible referents ("rain"), classical abstract concepts ("justice") and concrete concepts ("cup"), providing a gradient between fully concrete and fully abstract concepts in the blind. We find that anterior temporal lobe (ATL) responses track concept perceptibility and objecthood: preference for imperceptible object concepts was found in dorsal ATL, for abstract (non-object, non-referential) concepts in lateral ATL, and for perceptible concepts in medial ATL. These findings point to a new division-of-labor among aspects of ATL in representing conceptual properties that are abstract in different ways.