Early access to language supports number mapping skills in deaf children.

The ability to associate different types of number representations referring to the same quantity (symbolic Arabic numerals, signed/spoken number words, and nonsymbolic quantities), is an important predictor of overall mathematical success. This foundational skill-mapping-has not been examined in deaf and hard-of-hearing (DHH) children. To address this gap, we studied 188 4 1/2 to 9-year-old DHH and hearing children and systematically examined the relationship between their language experiences and mapping skills. We asked whether the timing of children's language exposure (early vs. later), the modality of their language (signed vs. spoken), and their rote counting abilities related to mapping performance. We found that language modality did not significantly relate to mapping performance, but timing of language exposure and counting skills did. These findings suggest that early access to language, whether spoken or signed, supports the development of age-typical mapping skills and that knowledge of number words is critical for this development.

The development of early numeracy in deaf and hard of hearing children acquiring spoken language.

Most deaf and hard-of-hearing (DHH) children are born to hearing parents and steered toward spoken rather than signed language, introducing a delay in language access. This study investigated the effects of this delay on number acquisition. DHH children (N = 44, meanage  = 58 months, 21F, >50% White) and typically-hearing (TH) children (N = 79, meanage  = 49 months, 51F, >50% White) were assessed on number and language in 2011-13. DHH children showed similar trajectories to TH children but delayed timing; a binary logistic regression showed that the odds of being a cardinal-principle (CP) knower were 17 times higher for TH children than DHH children, controlling for age (d = .69). Language fully mediated the association between deaf/hearing group and number knowledge, suggesting that language access sets the pace for number acquisition.

Language not auditory experience is related to parent-reported executive functioning in preschool-aged deaf and hard-of-hearing children.

Much research has found disrupted executive functioning (EF) in deaf and hard-of-hearing (DHH) children; while some theories emphasize the role of auditory deprivation, others posit delayed language experience as the primary cause. This study investigated the role of language and auditory experience in parent-reported EF for 123 preschool-aged children (Mage  = 60.1 months, 53.7% female, 84.6% White). Comparisons between DHH and typically hearing children exposed to language from birth (spoken or signed) showed no significant differences in EF despite drastic differences in auditory input. Linear models demonstrated that earlier language exposure predicted better EF (ß = .061-.341), while earlier auditory exposure did not. Few participants exhibited clinically significant executive dysfunction. Results support theories positing that language, not auditory experience, scaffolds EF development.

Successful communication does not drive language development: Evidence from adult homesign.

Constructivist accounts of language acquisition maintain that the language learner aims to match a target provided by mature users. Communicative problem solving in the context of social interaction and matching a linguistic target or model are presented as primary mechanisms driving the language development process. However, research on the development of homesign gesture systems by deaf individuals who have no access to a linguistic model suggests that aspects of language can develop even when typical input is unavailable. In four studies, we examined the role of communication in the genesis of homesign systems by assessing how well homesigners' family members comprehend homesign productions. In Study 1, homesigners' mothers showed poorer comprehension of homesign descriptions produced by their now-adult deaf child than of spoken Spanish descriptions of the same events produced by one of their adult hearing children. Study 2 found that the younger a family member was when they first interacted with their deaf relative, the better they understood the homesigner. Despite this, no family member comprehended homesign productions at levels that would be expected if family members co-generated homesign systems with their deaf relative via communicative interactions. Study 3 found that mothers' poor or incomplete comprehension of homesign was not a result of incomplete homesign descriptions. In Study 4 we demonstrated that Deaf native users of American Sign Language, who had no previous experience with the homesigners or their homesign systems, nevertheless comprehended homesign productions out of context better than the homesigners' mothers. This suggests that homesign has comprehensible structure, to which mothers and other family members are not fully sensitive. Taken together, these studies show that communicative problem solving is not responsible for the development of structure in homesign systems. The role of this mechanism must therefore be re-evaluated in constructivist theories of language development.