The role of cognitive factors on the development and evolution of the
      vocabulary
Creators: name: Brand, James Liam
Publisher: name: Publisher unspecified
Year: 2018

description: This thesis aims to explore how psycholinguistic factors can play a
      pivotal role in the way that the human lexicon is structured. Recent
      approaches to studying language have been heavily influenced by the
      principle that languages are shaped to suit the general learning and
      processing biases of the learner (Christiansen &amp; Chater, 2008).
      This view has gained considerable support from theoretical and empirical
      accounts from researchers in the fields of language acquisition and
      evolution. However, there has been little evidence that demonstrates how
      such learning biases may operate differently at various stages of an
      individual’s vocabulary development, or indeed how they may operate
      differently as the vocabulary subsequently evolves. Through a series of
      experimental studies, this thesis will examine how well documented
      psycholinguistic properties of words can shape the lexicon throughout the
      course of a language learner’s life, as well as the life of the language
      itself. Chapters 2 and 3 investigate how both arbitrariness and
      non-arbitrariness (in the form of sound-symbolism) make significant
      contributions to the way that languages are learnt. Central to this point
      is that important considerations should be made as to when and how these
      two properties are considered beneficial. Principally, these chapters
      focus on how the size of the vocabulary directly influences whether
      arbitrariness or non-arbitrariness is advantageous for the learner. We
      show that sound-symbolism facilitates learning individual form-meaning
      mappings when the vocabulary size is small, whereas as the vocabulary
      grows this advantage is only observed for distinguishing between
      categories. Which may explain why words acquired earlier in life, when the
      vocabulary size is small, are reported to be more sound-symbolic (Monaghan
      et al, 2014). Chapter 4 goes on to examine how variation in
      psycholinguistic properties of word can be used to directly predict
      variation in the fidelity of the word’s learning and production. By
      manipulating the frequency, length and age of acquisition of words learnt
      within an artificial language learning paradigm, this chapter aims to show
      how certain words are less vulnerable to change based on the way these
      properties offer significant processing advantages, whilst also
      considering the nature of the way errors are produced during recall by
      distinguishing between lexical adjustment and replacement. Importantly,
      these properties are investigated independent of one another, allowing for
      a significant contribution to be made to the way language change is
      studied. Following on from this, Chapter 5 then considers how these
      psycholinguistic properties may come to change the lexicon over the course
      of evolution. By using an iterated learning paradigm, the aim here is to
      observe how the changes reported in Chapter 4 may explain previously
      reported differences in the stability, and indeed instability, of lexical
      forms over a much longer timescale. This approach examines such
      differences through the cultural transmission of the languages across
      several generations of learners.