The Role of Language in the Development of Number Concepts: Evidence From and Towards an Understanding of Oral Deaf Cognition

Past research has suggested that language may play an important role in shaping the development of our fundamental concepts, such as number. Oral deaf children, by receiving less aural linguistic input than do typically hearing children of the same age, serve as an experimentally useful population for isolating the effects of language on number development. Because these children are otherwise cognitively typical, they allow for the role of language to be separated from other domain-general developmental factors. 98 typically hearing and 42 oral deaf children were tested both on a variety of number tasks measuring both verbally and nonverbally the two different cognitive systems at work in the development of number concepts, the analog-magnitude and the object-file system. These evolutionarily primitive systems theoretically develop independently of language. It was found that, as expected, differences in aural input and language development drove differences in verbal number development. Furthermore, language also drove differences in nonverbal development of the analog-magnitude system. Nonverbal object-file system development was unaffected by language delays. These findings indicate that language plays an important role in even nonverbal number development, suggesting that our fundamental concepts may be shaped, not just expressed, by language. These findings also have important implications for deaf educators and parents of deaf children, who may be unaware of the depth of cognitive repercussions of delaying aural language input. The language-independent development of the object-file system, though, is potentially useful for this community in understanding and addressing achievement gaps in deaf education. Language in Number Development: Oral Deaf Cognition 4