Interoceptive grounding of conceptual knowledge: new insight from an interoceptive-exteroceptive categorization task of concepts

The role of interoception, the perception of internal bodily signals, in shaping our understanding of concepts remains an intriguing and understudied area of research. Here, we investigate the interoceptive foundation of conceptual representation, particularly for abstract concepts compared to concrete ones. Employing a mouse-tracking paradigm, participants categorized abstract and concrete concepts as interoceptive (i.e., experienced through internal bodily sensations) or exteroceptive (i.e., experienced through the five perceptual senses), with the concepts varying in their degree of interoceptive grounding (emotional, philosophical, natural, artifact). The interoceptive dimension was particularly crucial for abstract-emotional concepts, as revealed by the lower likelihood of misclassifying them than the abstract-philosophical ones. Movement trajectories showed the implicit activation of interoceptive features during the categorization of concrete-natural concepts, thus beyond the abstract-emotional ones. To account for individual differences in attending to bodily signals, participants performed a cardioception task (heartbeat counting). Individuals with greater sensitivity to their heartbeat were faster in conceptual categorization, particularly when exteroceptively categorizing concrete-natural concepts. Taken together, our findings emphasize the multifaceted nature of conceptual knowledge, encompassing interoceptive dimensions alongside others.