War of the Words: Development of Inter-Lexical Inhibition in Typical Children

Spoken word recognition requires accessing the target word in the mental lexicon. It is now well known that as acoustic information unfolds over time, similar-sounding lexical candidates (e.g., cap and cat) compete until the disambiguating information (i.e., the last sound) is perceived and one word “wins”. As the word is activated it inhibits similar-sounding competitors. While this inter-lexical inhibition between words has been demonstrated in adults (Dahan, Magnuson, Tanenhaus, & Hogan, 2001; Luce & Pisoni, 1998), it is unclear how it develops. The present study used an eye-tracking paradigm to examine this inhibition in school-aged children. Participants heard words and matched them to their picture from a screen containing four pictures. Words were manipulated with cross-splicing to briefly activate a competitor and observe the resulting interference on the target word. Eye-movements to each picture were monitored to measure how strongly words compete during recognition. We found that both 7- to 8-year-old children and 12- to 13-year old children made fewer fixations to the target when the onset of the target word (e.g., cap) came from a competitor word (e.g., ca(t)p) than from a nonword (e.g., ca(ck)t). This suggests that activation of the competitor led to inhibition of the target word, resulting in less activation of the target word. There were differences in this marker of inhibition across age groups, suggesting that lexical competition undergoes developmental change even in the later years of childhood. Analyses of assessments of language, reading, perceptual reasoning, and general inhibition reveal a potential relationship between inter-lexical inhibition and reading fluency, but none with vocabulary or general inhibition.