Investigating the role of spatial perception in literal and metaphorical language comprehension

The human brain seamlessly integrates information across cognitive domains, flexibly adapting to changing environmental demands. Yet, the neural mechanisms underlying this dynamic integration-especially how perceptual input shapes language comprehension-remain insufficiently understood. We investigated how vertical spatial perception is integrated into the processing of both literal and metaphorical spatial words. Time-frequency analyses revealed language-space congruency effects for both word types but with distinct oscillatory patterns: a theta-alpha-low beta ERS for literal spatial words, and a high beta-gamma ERD for metaphorical spatial words. However, these effects were not replicated in the ERP data. The ERP results demonstrated that, for literal spatial words, downward items elicited a more positive LPC, indicating an upward processing advantage, conversely, for metaphorical spatial (emotion-laden) words, downward (negative) items elicited more positive P200, N400, and LPC, indicating a downward processing advantage. Collectively, these findings show that spatial perception influences word processing through cross-modal interaction, supporting embodied cognition while refuting purely amodal accounts. Moreover, the discrepancies between time-frequency and ERP results, as well as the distinct oscillatory patterns and location processing advantages for literal versus metaphorical spatial words, challenge strong embodied view and provide novel evidence that spatial perception modulates language comprehension via context-dependent neural dynamics.