Multiplex model of mental lexicon reveals explosive learning in humans

Abstract

Word similarities affect language acquisition and use in a multi-relational way barely accounted for in the literature. We propose a multiplex network representation of this mental lexicon of word similarities as a natural framework for investigating large-scale cognitive patterns. Our representation accounts for semantic, taxonomic, and phonological interactions and it identifies a cluster of words which are used with greater frequency, are identified, memorised, and learned more easily, and have more meanings than expected at random. This cluster emerges around age 7 through an explosive transition not reproduced by null models. We relate this explosive emergence to polysemy – redundancy in word meanings. Results indicate that the word cluster acts as a core for the lexicon, increasing both lexical navigability and robustness to linguistic degradation. Our findings provide quantitative confirmation of existing conjectures about core structure in the mental lexicon and the importance of integrating multi-relational word-word interactions in psycholinguistic frameworks.

Multiplex networks quantify robustness of the mental lexicon to catastrophic concept failures, aphasic degradation and ageing

“…Multiplex PageRank was based on versatility 41,54 . Multiplex betweenness and centrality exploited multilayer paths, like in previous works 26,29,55 .…”

“…These quantitative experiments are called network attacks and are used for investigating the robustness of networked systems to random or targeted damage 9,[21][22][23][24][25] . Although it is appealing to investigate robustness of single aspects of the mental lexicon to degradation, this approach would neglect the extensive evidence indicating how failed lexical retrieval crucially depends on the interplay between semantic and phonological conceptual similarities 3,6,8,26,27 . In order to embrace multiple aspects of the mental lexicon in a single network representation, this work suggests studying lexicon robustness through a minimal representation of semantic and phonological associations for 16000 English words as a multiplex lexa) Electronic mail: massimo.stella@inbox.com ical network 26,[28][29][30][31] .…”

“…Although it is appealing to investigate robustness of single aspects of the mental lexicon to degradation, this approach would neglect the extensive evidence indicating how failed lexical retrieval crucially depends on the interplay between semantic and phonological conceptual similarities 3,6,8,26,27 . In order to embrace multiple aspects of the mental lexicon in a single network representation, this work suggests studying lexicon robustness through a minimal representation of semantic and phonological associations for 16000 English words as a multiplex lexa) Electronic mail: massimo.stella@inbox.com ical network 26,[28][29][30][31] . Such representation is used as a quantitative framework for exploring the large-scale robustness of the mental lexicon under progressive word failure through the formalism of network-based attacks 20,22,23,25 .…”

“…paths connecting the same two words through free associations only and, at the same time, through phonological associations only. The largest viable component of the mental lexicon was identified 26 as a network core for the mental lexicon, thus facilitating network navigation, and emerging through an explosive phase transition in children around age 7-8 yrs. Subsequent work 30 identified the largest viable cluster as a relevant component of the mental lexicon, made of more frequent, easier to identify, earlier acquired words, of relevance also for knowledge exploration across groups with different levels of creativity.…”

From Topic Networks to Distributed Cognitive Maps: Zipfian Topic Universes in the Area of Volunteered Geographic Information

“…See Boccale i et al [16] for a comprehensive overview of related notions whose formalism is used here. See Stella et al [129] for an example of a multiplex network of lexical systems.…”