Impact of Language Experience on Early Numerical Cognition
The objective of the study is to evaluate longitudinally the impact of language modality and early language experience on the core numerical representation and on the acquisition of the concept of exact number. To do this, 180 children aged 3 to 5 will be followed for up to two years. Leveraging the natural variability occurring within the deaf community, 60 children will be native American Sign Language (ASL) users, 60 children will have been exposed to a visual language after 24 months of age (e.g., deaf children with late cochlear implant and no in-home visual language), and the remaining will be English speaking children with no hearing loss and no delay in language exposure. Children will be evaluated at ~8 months intervals, between 2 to 4 times, on basic number skills until they reach proficient understanding of the exact number concept. They will also be assessed for language skills and general IQ. Parents will fill out a comprehensive survey on their child's language use and in-home language. This paradigm will allow to determine the impact of language modality and proficiency on the developmental trajectory of the core numerical representation. It will also allow to determine if the stages for reaching a full understanding of the exact number concept can be delayed or facilitated depending on language modality. Could the use of fingers in ASL to represent numbers facilitate early number concept acquisition? Does a delay in language exposure impact both the core number system and the acquisition of formal number concepts? Are the different stages impermeable to early language experience? What role does language play in the relation between the core numerical representation and the acquisition of exact number concept? These long-standing questions in the field of numerical cognition can be uniquely answered through the perspective of a visual language and time of language exposure.