Semantic grounding is the process of relating meaning to symbols (e.g., words). It is the foundation for creating a representational symbolic system such as language. Semantic grounding for verb meaning is hypothesized to be achieved through two mechanisms: sensorimotor mapping, i.e., directly encoding the sensorimotor experiences the verb describes, and verb-category mapping, i.e., encoding the abstract category a verb belongs to. These two mechanisms were investigated by examining neuronal-level spike (i.e. neuronal action potential) activities from the motor, somatosensory and parietal areas in two human participants. Motor and a portion of somatosensory neurons were found to be involved in primarily sensorimotor mapping, while parietal and some somatosensory neurons were found to be involved in both sensorimotor and verb-category mapping. The time course of the spike activities and the selective tuning pattern of these neurons indicate that they belong to a large neural network used for semantic processing. This study is the first step towards understanding how words are processed by neurons.
Yang, Y., Dickey, M. W., Fiez, J., Murphy, B., Mitchell, T., Collinger, J., Tyler-Kabara, E., Boninger, M., & Wang, W. (2017). Sensorimotor experience and verb-category mapping in human sensory, motor and parietal neurons. Cortex, 92, 304–319. https://doi.org/10.1016/j.cortex.2017.04.021