Semantic Representations Are Updated Across the Lifespan Reflecting Diachronic Language Change

Humans learn the meanings of words from the contexts in which they are used. Patterns of language use change over time, suggesting that the contexts in which some words are experienced change across an individual's lifespan. Here, we investigated whether language users' semantic space changes in lockstep with changes in the language or whether it retains traces of historical language use/meanings. In two studies, we used distributional semantic word embeddings trained on corpora from different decades (HistWords) to capture meaning change at the level of the (English) language. We first compared these diachronic semantic spaces to the semantic spaces of individuals in different age cohorts (ranging from people in their 20s to people over 70) using an open dataset of associations norms (Small World of Words). Then, using HistWords, we sampled English words that have changed in meaning and words that have maintained the same meaning/usage patterns between the 1950s and the 1990s and collected relatedness judgments for those words with their nearest neighbors from each decade (1950s and 1990s) from both younger (18-33 years) and older (63-92 years) adults. Across the two studies, the semantic spaces of both older and younger adults were most strongly correlated with the semantic spaces derived from more recent corpora. We found little evidence of historical semantic spaces being differentially predictive of the semantic spaces of older adults relative to those of young adults. Our findings suggest that individuals continuously and rapidly update their lexico-semantic representations regardless of age, such that word meanings learned earlier in life are largely replaced with new meanings derived from later language experience.