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

Abstract

This study investigated the developmental timecourse 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 nine-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 et al, 2010) which 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 differences due to developmental change may derive from different sources than individual differences in relative language ability.

Waiting for lexical access: Cochlear implants or severely degraded input lead listeners to process speech less incrementally

“…To quantify these differences we used a non-linear curve fitting technique developed in prior studies (Farris-Trimble & McMurray, 2013; McMurray et al, 2010; Rigler et al, 2015) that estimates the precise shape of the timecourse of looking to each competitor for each participant. Nonlinear functions were fit to each participant’s data, and their parameters were analyzed as descriptors of the timecourse of processing.…”

“…To examine this statistically, timecourse functions (Figure 3) for each participant were smoothed with a 48 msec (12 frame) triangular window. We then derived three new measures from these difference curves (see Brouwer & Bradlow, 2015; Rigler et al, 2015, for similar analyses). First, we found the maximum of each participant’s function ( peak fixations ), which can be seen as the overall amount of early competition.…”

“…All of the non-young-adult groups that have been studied to date exhibit some form of immediate competition. This includes toddlers (Fernald, Swingley, & Pinto, 2001; Swingley, Pinto, & Fernald, 1999), adolescents (Rigler et al, 2015) children with SLI (Dollaghan, 1998; McMurray, Samelson, Lee, & Tomblin, 2010), people undergoing cognitive aging (Revill & Spieler, 2012), and postlingually deafened adults who use cochlear implants (CIs) (Farris-Trimble, McMurray, Cigrand, & Tomblin, 2014). While the dynamics of lexical access in these groups differs quantitatively (and in interesting ways) from typical adults, all of these groups also exhibit behavior broadly consistent with immediate competition.…”

“…As in that study, we examined early eye-movements to onset (cohort) and offset (rhyme) competitors to assess how immediately CI users activate lexical candidates. This technique has been used with older children (Rigler et al, 2015; Sekerina & Brooks, 2007), and a variety of clinical populations including individuals with language impairment (McMurray et al, 2010), aphasia (Yee, Blumstein, & Sedivy, 2008), and postlingually deafened CI users (Farris-Trimble et al, 2014). The version used here has good test/re-test reliability (Farris-Trimble & McMurray, 2013).…”

“…Highly similar experiments have examined the dynamic of lexical processing as a result of each factor singly, and found distinct effects on the timecourse of activation. Typically developing adolescents (between 9 and 16) show an over abundance of initial competition from cohorts and rhymes, and consequently somewhat slower target activation (Rigler et al, 2015) (see also, Sekerina & Brooks, 2007); however, by the end of processing even 9 year olds fully suppress competitors. In contrast adolescents with poorer language (language impairment) show no early effects on competition but do not fully suppress lexical competitors by the end of processing (McMurray, Munson, & Tomblin, 2014; McMurray et al, 2010) (see also, Dollaghan, 1998), and, as described, post-lingually deaf CI users are somewhat slower to activate target words, and also maintain competitors later.…”