Iza, M. , Rodriguez, J. M. , Calleja, M. , Garcia, J. & Damas, J.
University of Malaga
Usually deaf children show lower scores in numerical tasks than normal hearing peers. Explanation of mathematical disabilities in hearing children are based on a quantity representations deficit (Geary 1994) or on an access deficit to such representations (Rousselle&Noël 2008). The aim of this study is to verify whether deaf people show a deficit in representation or in access to numerical representations by using both symbolic (Arabic digits) and non-symbolic (dot constellations and hands) magnitude comparison tasks. 10 profoundly deaf children using cochlear implants (mean age 9) and 10 normal-hearing children, matched in IQ, visual STM, oral language skills and age, participated in the study. Numerical distance (1vs3-4) and magnitude (1-5vs5-9) were manipulated. RT analysis show a significant interaction TaskxGroup [F(2,36)=3.68; p=.035]: No differences were found between both groups in non-symbolic comparison tasks, however deaf participants were slower than hearing participants in the symbolic task Magnitude and distance effects were found across groups and tasks. Our results suggest that magnitude representations are similar in both groups. However, deaf children seem to have difficulties in accessing magnitude representations through symbolic codes. Following Budgen&Ansari (2011), a slower activation of semantic numerical information might explain deaf children lower scores in numerical tasks.