作為文學修辭手段的通感很早便受到學者的關注。認知語言學將通感從文學修辭這一語言現象上升到思維層面加以研究，認為通感的本質是作為人類重要認知方式的概念隱喻。通感有作為語言修辭的通感，也具有作為心理機制的通感；隱喻有作為語言修辭的隱喻，以及作為認知機制的隱喻（概念隱喻）；多模態隱喻是隱喻中的一個特殊情況，也有修辭和認知心理兩個層面上的意義。作為心理認知的隱喻是廣義的，其本質是以一種事物去理解和體驗另一種事物。同樣，作為心理認知的多模態隱喻中的“隱喻”也是廣義的，其本質也是以一種事物去理解和體驗另一種事物，只不過該過程涉及了兩種或兩種以上的感官模態。多模態隱喻具有語言修辭、視覺畫面或聽覺聲音等多個層次上的意義。多模態隱喻在語言文學中以通感這一修辭手法體現，能夠使讀者或聽者調用日常多模態互動的感官經驗，對描寫對象產生更為形象、鮮活的認知。作為語言修辭方法的通感及多模態隱喻是相應認知心理機制在語言中的體現；作為認知心理機制的通感及多模態隱喻可體現為隱喻、明喻等多種文學修辭格；通感與多模態隱喻作為認知心理機制可映射於人類與外界交互的多種介面上。

Synaesthesia as a literature rhetoric device has received much attention from scholars. Cognitive linguistics studies synaesthesia at the cognitive level and argues that synaesthesia is a conceptual metaphor as an important cognitive method. Multimodal Metaphor, which is a heated topic in todays metaphor studies, offers a new perspective in the study of synaesthesia as a literature rhetoric device. Both synaesthesia and multimodal metaphor can be considered from the perspectives of language rhetoric and cognitive mechanism. This paper discusses the relation among synaesthesia, metaphor and multimodal metaphor by reviewing previous literature, and some examples are in-detail introduced. Metaphor in the cognitive scale, or conceptual metaphor, whose nature is to provide people the mechanism to understand or experience one item through the other, can be reflected in many ways of language rhetoric. Multimodal metaphor has the same property despite more modalities are involved. Both synaesthesia or multimodal metaphor can be found in language rhetoric, arts creation, aesthetic activities and many other interfaces of daily life since they are regarded as a cognitive mechanism of human beings.