Modeling the Memory-Surprisal Trade-Off over Time: Communicative Efficiency Decreases with Lexico-Grammatical Change in Scientific English
Proceedings of the Fifteenth Language Resources and Evaluation Conference (LREC 2026)
Abstract
The memory-surprisal trade-off (MST) has been shown to hold cross-linguistically as a general principle of communicative efficiency: languages that exhibit information locality tend to have word orders that allow for efficient memory use, i.e., lower surprisal at a fixed memory budget. In this paper, we explore the influence of diachronic variation on the MST. We compare scientific English in the Royal Society Corpus (RSC, 18thc. – 20thc.) to "general language" in the Corpus of Historical American English (COHA) to assess the impact of intra-linguistic variation (register). We find that both time and register influence the shape of the tradeoff: Over time, vocabulary expansion raises minimal surprisal, while the shape of the MST curves changes. Decreasing distances between syntactic dependencies due to more local nominal encodings change how predictive information is distributed across memory scales. The effects are stronger for the RSC than for COHA.