Poster #41 - Signed or Spoken Number Word Knowledge Predicts Deaf and Hard of Hearing Children’s Numeracy Skills

• In Event: 2-055 - Poster Session 06
  In Poster Session: PS 06 Section - Cognitive Processes

Integrative Statement

Children’s early numeracy skills are critical for mathematical and academic success (Duncan, Dowsett, Claessens, Magnuson, Huston, Klebanov, & Japel, 2008). Carey’s (2009) bootstrapping hypothesis posits that the number words comprising the count list (e.g.,“one”,“two”,“three”) serve as placeholders, and that between ages 2 and 4 years, children slowly associate them with exact quantities. In hearing children, variability in language input influences this timeline (Gunderson & Levine, 2011).
Deaf and hard-of-hearing (DHH) children experience much greater variability in language input. Fewer than 10% have full access from birth to American Sign Language (Mitchell & Karchmer, 2004); the vast majority experience delayed language exposure, which negatively affects both language and cognitive development (Mayberry, 2010). Deaf children perform worse on tests of mathematics achievement than typically-hearing peers (Gottardis, Nunes, & Lunt, 2011; Shusterman, Berkowitz, & Lange, 2012), but when controlling for number list knowledge, hearing and deaf native language users showed comparable competence (Secada, 1984).
Working with 47 hearing children and 93 deaf children, we asked how number acquisition is affected by the 1) modality of language input (signed vs. spoken) and 2) timing of language exposure (beginning at birth or after birth). In their preferred language, we assessed children’s ability to count a set of 20 objects (Number List, a proxy for number input/experience), and their knowledge of meanings for specific spoken or signed numerals (Give-N; Wynn, 1990). In Give-N, children provide a requested number of fish; quantities 1-6 were each assessed 3 times; children who answered “6” correctly were assessed once on 7, 9, 10, 12, and 16. Our dependent measure was the highest quantity given correctly. We found that the timing of language exposure, but not language modality, significantly predicted children’s number acquisition. This suggests that neither sign language experience nor deafness per se hinders number acquisition; rather, the delay results from later language exposure.
Data visualization (Figure 1) showed that the Later-exposed group (orange squares) formed two sub-groups: one showing typical progression and one delayed (see cluster of orange squares in the lower-right quadrant). Using the fitted values for a 50th quantile regression (expected scores), we categorized participants as “Higher-Give-N” or “Lower-Give-N”. A logistic regression found that children’s Number List performance and Age each significantly predicted membership in the Higher- or Lower-Give-N groups, but Socioeconomic status (SES) and Language Modality did not (Table 1).
Thus, knowing the count list is critical for foundational numeracy skills that underlie later math performance. It is perhaps unsurprising that these skills influence children’s ability to generate sets of specific sizes—however, this is the first large-scale study to show definitively that facility with the count list drives resilience in the development of basic numeracy in DHH children who have experienced delays in exposure to language. These findings counter prior research arguing that early use of sign language hinders linguistic and cognitive development (e.g.,Geers, Mitchell, Warner-Czyz, Wang, & Eisenberg, 2017). This work highlights the importance of early language access, especially exposure to and practice using a count list, for all children, regardless of language modality.

Authors

• Emily Carrigan, Elon University
  Presenting Author

• Anna Shusterman, Wesleyan University
  Non-Presenting Author

• Marie Coppola, University of Connecticut
  Non-Presenting Author