The slow developmental time course of real-time spoken word recognition

Abstract

This study investigated the developmental time course of spoken word recognition in older children using eye tracking to assess how the real-time processing dynamics of word recognition change over development. We found that 9-year-olds were slower to activate the target words and showed more early competition from competitor words than 16-year-olds; however, both age groups ultimately fixated targets to the same degree. This contrasts with a prior study of adolescents with language impairment (McMurray, Samelson, Lee, & Tomblin, 2010) that showed a different pattern of real-time processes. These findings suggest that the dynamics of word recognition are still developing even at these late ages, and developmental changes may derive from different sources than individual differences in relative language ability.

Figure 1

Proportion of fixations as a function of time and LI status in McMurray et al., (2010). A) Fixations to target object; B) Fixations to cohort competitor; C) Fixations to rhyme competitor.

Figure 2

Proportion of fixations to each word type by participant group on TCRU trials (correct trials only). A) Nine-year-olds. B) Sixteen-year-olds. Vertical lines mark the earliest time we would expect signal driven looks to objects (i.e. 200 ms to plan and launch eye movement and the 100 ms of silence at the beginning of the trial) and the average offset time of our auditory stimuli

Figure 3

Proportion of fixations to each word type on TCRU trials, as a function of time by age group. A) Fixations to target. B) Fixations to Cohort. C) Fixations to rhyme. D) Fixations to unrelated. Vertical lines mark the earliest time we would expect signal driven looks to objects (i.e. 200 ms to plan and launch eye movement and the 100 ms of silence at the beginning of the trial) and the average offset of the auditory stimuli

Figure 4

A) The difference between the proportion of fixations to cohort and unrelated competitors as a function of time and age. B) Difference between roportion of fixations to rhyme competitors and unrelated competitors.