Decoding Linguistic Synesthesia in Chinese: Evidence From Directional Preferences and Hemispheric Processing Mechanism

Linguistic synesthesia, characterized by cross-modal sensory mappings, is frequently associated with metaphor and neurological synesthesia. However, while prior research has emphasized these latter phenomena, the cognitive and neural underpinnings of linguistic synesthesia remain poorly understood. This study employs the divided visual field (DVF) paradigm to examine the hierarchical organization and hemispheric lateralization of synesthetic transfers in Chinese word pairs, while establishing theoretical links between linguistic synesthesia mechanisms, metaphorical cognition, and neurological synesthesia. Results demonstrated that linguistic synesthesia in Chinese involves unidirectional, bidirectional, and biased-directional transfer patterns, with no consistent dominance of forward mappings (e.g., touch→sight) or backward mappings (e.g., sight→touch). Participants exhibited enhanced accuracy in taste-smell transfers, likely due to established neuroanatomical overlap, and reduced performance in auditory-visual transfers, consistent with hierarchical models of sensory processing. Hemispheric analysis revealed no significant lateralization, indicative of distributed bilateral neural networks. These findings posit linguistic synesthesia as a phenomenon rooted in sensory perception, sharing cognitive foundations with metaphor and neurological synesthesia while retaining distinct characteristics. The study illuminates the interplay between sensory perception, language, and cognition, offering insights for neuro-linguistic frameworks and cross-modal research.