Symbol Grounding and Meaning: A Comparison of High-Dimensional and Embodied Theories of Meaning

Latent Semantic Analysis (Landauer & Dumais, 1997) and Hyperspace Analogue to Language (Burgess & Lund, 1997) model meaning as the relations among abstract symbols that are arbitrarily related to what they signify. These symbols are ungrounded in that they are not tied to perceptual experience or action. Because the symbols are ungrounded, they cannot, in principle, capture the meaning of novel situations. In contrast, participants in three experiments found it trivially easy to discriminate between descriptions of sensible novel situations (e.g., using a newspaper to protect one's face from the wind) and nonsense novel situations (e.g., using a matchbook to protect one's face from the wind). These results support the Indexical Hypothesis that the meaning of a sentence is constructed by (a) indexing words and phrases to real objects or perceptual, analog symbols; (b) deriving affordances from the objects and symbols; and (c) meshing the affordances under the guidance of syntax.