The grounding of abstract concepts in the sensory-motor, mentalizing and social interaction brain systems: A multiple representation framework.

For decades, theorizing in the cognitive sciences was dominated by the assumption that abstract concepts, lacking directly perceivable referents, can only be represented and processed through amodal or verbal linguistic representations. More recently, refined hybrid grounded cognition theories have successfully been applied to account for abstract concepts within a multiple representation framework. According to this perspective, the meaning of abstract concepts is constituted by representations distributed across various experiential modal brain systems, including sensory, motor, emotional, mentalizing, and social interaction networks. Representations in these modal systems are complemented by representations in language-related and amodal hub regions, depending on the specific semantic content of the concept. In this article, we first outline a multiple representation framework within a hybrid grounded cognition approach and then review neuroscientific evidence concerning the neural substrate of abstract concepts related to sensory-motor features, mental states and social constellations. These findings indicate that modal sensory-motor, mentalizing, and social interaction brain systems contribute to the processing of particular types of abstract concepts, alongside representations in amodal semantic hub regions and language areas. Moreover, this body of research demonstrates that different modal neural circuits are engaged as a function of a concept's specific semantic content, thereby highlighting the heterogeneity of abstract concepts. Future research should address outstanding questions, including the precise functional contributions of distinct neural circuits to the representation of abstract concepts and the evaluation of predicted patterns of impairment in neurological and psychiatric patient populations.