Knowledge structures are flexible. This is exemplified by language. The sentence “She got cash from the bank” does not make us think about the bank of a river. Our brains must house representations of word meaning that are constrained by the stable form of the word, but also by flexibly changing contexts. Here, we quantified the effect of flexibly changing sentential context on word representations relative to that of stored word form.
Participants learned to associate symbols with homonyms, where they derived the homonym’s meaning from its sentence context (e.g.,“she got cash from the [bank]”). Word meaning flexibility was estimated with: (1) a spatial multi-arrangement task, where participants positioned the symbols in a space based on their associated word meaning, and (2) a repetition priming task, where participants made speeded judgements about a sequence of symbols.
The spatial multi-arrangement task successfully captured the flexibility of word meaning, showing larger distances between symbols associated with homonyms (e.g., river- vs cash-bank) than between isonyms (e.g., river- vs river-bank). This effect was as large as that of stable word-form (e.g., “bank” vs “chair”). Ongoing fMRI work will address the role of hippocampus-medial frontal circuitry in representing these flexible context-dependent versus stored word-form representations.