Direct and Indirect Novel Word Learning Abilities for Children With Developmental Language Disorder

• In Event: Communication Outcomes for Differently-abled Individuals: Factors associated with Language Development and Accessibility

Abstract

Children with developmental language disorder (DLD) perform 0.60 SDs lower, on average, on measures of word learning than age-matched peers with typical language development (Kan & Windsor, 2010). Although they need more exposures to learn new words than their peers, once they have learned, their retention is intact; thus, it appears that encoding is a weakness but consolidation is a strength (McGregor, Arbisi-Kelm, Eden, & Oleson, 2020). However, that conclusion is based on studies in which words were taught directly. Only Rice and colleagues (1990; 1992; 1994) have examined word learning and retention in response to indirect exposure, and they reported weaknesses in both learning and retention. The current study is the first to systematically examine how these different contexts (direct vs. indirect) affect novel word learning and retention for children with DLD.

Thirty-six children with DLD and 45 with typical development (TD), ages of 6 to 8 years, participated (see comparison in Table 1). On day 1, children were taught the names of 12 novel objects directly or indirectly (between-subjects). For direct instruction, children were shown one image at a time and heard a label (This is a blavid). For indirect instruction, children were shown two images (one novel, one familiar with a known name) and responded via keypress to a question about the novel object (Are the antenna of the blavid pointing down?). Learning was tested on day 1 and retention was tested 24 hours later via a 3AFC task in which children heard three phonological neighbors (two foils and a target) and touched a dot (left, center, or right) that corresponded to the one that was in their training set.

On day 1, the effect of instruction significantly differed between groups, b=0.29, p<.01 (Figure 1). Children in the TD group were more accurate in recognizing the forms of words taught via direct (M=69%) than indirect (M=44%) instruction, b=0.24, p<.01. Children in the DLD group, however, were equally accurate with both direct (M=30%) and indirect (M=34%) instruction, b=0.04, p=.52.

On day 2, this pattern held except that both groups performed better than on day 1. For children with DLD, their accuracy in recognizing word forms was significantly lower than the TD group on both days, p’s <.01. The boost in accuracy from day 1 to 2 (~15%), however, did not differ between groups, b=0.04, p=0.34.

Compared to TD peers, children with DLD struggled to encode the forms of novel words, but did not struggle with retention. Without any intervening exposure to the novel words, both groups experienced the same boost in accuracy when identifying the correct forms of the novel words one day later, a sign of intact consolidation. Our findings also suggest that children with DLD benefit less than their peers with TD from direct instruction. Additional findings (not reported here), suggest that children with DLD similarly struggled to encode, but not retain, the referents and semantic categories associated with the novel words.

Authors

• Ron Pomper, Boys Town National Research Hospital
  Presenting Author

• Karla McGregor, Boys Town National Research Hospital
  Non-Presenting Author

• Nichole Eden, Boys Town
  Non-Presenting Author

• Timothy Arbisi-Kelm, Boys Town
  Non-Presenting Author

• Nancy Ohlmann, Boys Town
  Non-Presenting Author