Linking memory activation and word adoption in social language use via rational analysis

This paper investigates how cognition facilitates the adoption of new words through a study of the large-scale Reddit corpus, which contains written, threaded conversations conducted over the internet. Parameters for the cognitive architecture are estimated. Using ACT-R's account of declarative memory, the activation of memory chunks representing words is traced and compared to usage statistics sampled from a year of data. Potential values for decay and retrieval threshold are identified according to model fit and growth rates of word adoption. The resulting estimate for the decay parameter, d, is 0.22, and the estimate for the retrieval threshold parameter, rt, lies between 3.4 and 4.5.