11.03.2025 Kita Sotaro

Abstract: I will discuss four psychological foundations of human language. First, human language consists of two qualitatively different meaning encoding systems that are tightly linked with each other.  One is a propositional system that encodes meaning with a linear combination of discrete meaning bearing units (e.g., words). The other is an imagistic system that encodes meaning based on similarity and spatial contingency (e.g., iconic and pointing gesture). The two systems are interlinked with each other. For example, grammatical structures of languages are closely coupled with the way iconic gestures represent motion events.  Second, the linear and discrete encoding scheme for the propositional system is developmentally resilient.  For example, features like linear and segmented structure, discrete form units and duality of patterning all emerge in sign/gesture communication systems of deaf children with minimal conventional language input (signers of Nicaraguan Sign Language, Home Signers). Third, the meaning encoding systems transcends sensory modality. The flexibility between spoken and signed languages is a clear example. Even, the imagistic system encodes meaning that transcends sensory modalities. For example, sound symbolic words derive meaning from two converging similarity mappings: acoustics-to-referent similarity and articulation-to-referent similarity. The evidence for this comes from sound symbolic judgement by orally trained Deaf individuals. Fourth, humans can rapidly create a symbol that are communicatively efficient. For example, when hearing speakers create "silent gestures" to represent concepts (e.g., 'apple'), they can take a perspective of comprehenders and create easily understandable gestures within seconds. In conclusion, human language is a resilient and adaptive system grounded in both propositional and imagistic representation systems to communicate a broad range of messages in an efficient way.