The mathematical achievements of deaf children from different educational environments

Number Stroop Effects in Arabic Digits and ASL Number Signs: The Impact of Age and Setting of Language Acquisition

Multiple studies have reported mathematics underachievement for students who are deaf, but the onset, scope, and causes of this phenomenon remain understudied. Early language deprivation might be one factor influencing the acquisition of numbers. In this study, we investigated a basic and fundamental mathematical skill, automatic magnitude processing, in two formats (Arabic digits and American Sign Language number signs) and the influence of age of first language exposure on both formats by using two versions of the Number Stroop Test. We compared the performance of individuals born deaf who experienced early language deprivation to that of individuals born deaf who experienced sign language in early life and hearing second language learners of ASL. In both formats of magnitude representation, late first language learners demonstrated overall slower reaction times. They were also less accurate on incongruent trials but performed no differently from early signers and second language learners on other trials. When magnitude was represented by Arabic digits, late first language learners exhibited robust Number Stroop Effects, suggesting automatic magnitude processing, but they also demonstrated a large speed difference between size and number judgments not observed in the other groups. In a task with ASL number signs, the Number Stroop Effect was not found in any group, suggesting that magnitude representation might be format-specific, in line with the results from several other languages. Late first language learners also demonstrate unusual patterns of slower reaction time for neutral rather than incongruent stimuli. Together, the results show that early language deprivation affects the ability to automatically judge quantities expressed both linguistically and by Arabic digits, but that it can be acquired later in life when language is available. Contrary to previous studies that find differences in speed of number processing between deaf and hearing participants, we find that when language is acquired early in life, deaf signers perform identically to hearing participants.

Dysnumeria in Sign Language: Impaired Construction of the Decimal Structure in Reading Multidigit Numbers in a Deaf ISL Signer

We report on the first in-depth analysis of a specific type of dysnumeria, number-reading deficit, in sign language. The participant, Nomi, is a 45-year-old signer of Israeli Sign Language (ISL). In reading multidigit numbers (reading-then-signing written numbers, the counterpart of reading aloud in spoken language), Nomi made mainly decimal, number-structure errors- reading the correct digits in an incorrect (smaller) decimal class, mainly in longer numbers of 5-6-digits. A unique property of ISL allowed us to rule out the numeric-visual analysis as the source of Nomi's dysnumeria: In ISL, when the multidigit number signifies the number of objects, it is signed with a decimal structure, which is marked morphologically (e.g., 84 → Eight-Tens Four); but a parallel system exists (e.g., for height, age, bus numbers), in which multidigit numbers are signed non-decimally, as a sequence of number-signs (e.g., 84 → Eight, Four). When Nomi read and signed the exact same numbers, but this time non-decimally, she performed significantly better. Additional tests supported the conclusion that her early numeric-visual abilities are intact: she showed flawless detection of differences in length, digit-order, or identity in same-different tasks. Her decimal errors did not result from a number-structure deficit in the phonological-sign output either (no decimal errors in repeating the same numbers, nor in signing multidigit numbers written as Hebrew words). Nomi had similar errors of conversion to the decimal structure in number comprehension (number-size comparison tasks), suggesting that her deficit is in a component shared by reading and comprehension. We also compared Nomi's number reading to her reading and signing of 406 Hebrew words. Nomi's word reading was in the high range of the normal performance of hearing controls and of deaf signers and significantly better than her multidigit number reading, demonstrating a dissociation between number reading, which was impaired, and word reading, which was spared. These results point to a specific type of dysnumeria in the number-frame generation for written multidigit numbers, whereby the conversion from written multidigit numbers to the abstract decimal structure is impaired, affecting both reading and comprehension. The results support abstract, non-verbal decimal structure generation that is shared by reading and comprehension, and also suggest the existence of a non-decimal number-reading route.

Uma intervenção em contagem com duas crianças surdas

Este estudo de caso investigou se crianças surdas, filhas de pais surdos, estão em vantagem para aprender conceitos numéricos comparados com crianças surdas, filhas de pais ouvintes. Comparamos a resposta à intervenção de duas crianças de 6 anos de idade: um menino sinalizante nativo e uma menina que entrou em contato com a língua de sinais a partir dos 2 anos de idade. Ambos participaram de uma intervenção breve projetada para melhorar a compreensão da composição aditiva e o uso de procedimentos econômicos de contagem na resolução de problemas. Contrariamente às nossas expectativas, as crianças alcançaram níveis semelhantes no uso de procedimentos de contagem, na compreensão aditiva do número e também no aumento do campo numérico.

Observando estratégias e buscando soluções: a resolução de operações por adolescentes surdos

No presente artigo, relatam-se resultados parciais de uma investigação sobre as estratégias de resolução de operações (adição e subtração), realizada com sete adolescentes surdos profundos prélinguísticos, na faixa etária entre os 12 anos e quatro meses e os 15 anos e 11 meses, em situação de interação entre pares. A partir dos resultados, elaboram-se algumas recomendações didáticas a fim de melhorar o rendimento matemático desta população. A interpretação dos tipos de erro e o conhecimento das estratégias utilizadas pelos alunos constituem aspectos relevantes para a melhora do desenvolvimento profissional dos professores. Alguns dos tipos de erro detectados apresentam características específicas, diferentes das que são previamente descritas na literatura.

Habilidades matemáticas iniciais em crianças surdas e ouvintes

O presente estudo tem como objetivo investigar o conhecimento de procedimentos e conceitos matemáticos em crianças surdas da educação infantil. Até o momento, existe uma grande escassez de estudos sobre o desenvolvimento de conceitos e procedimentos matemáticos em crianças surdas de idade pré-escolar. Os poucos trabalhos existentes sugerem que as crianças surdas têm dificuldades em aprender a sequência numérica. Contudo, não há qualquer evidência conclusiva a respeito das causas desta dificuldade. Os resultados deste estudo revelaram que as diferenças de desempenho entre crianças surdas e ouvintes estão relacionadas com a demanda linguística.

Counting in sign language

Do the visuomanual modality and the structure of the sequence of numbers in sign language have an impact on the development of counting and its use by deaf children? The sequence of number signs in Belgian French Sign Language follows a base-5 rule while the number sequence in oral French follows a base-10 rule. The accuracy and use of sequence number string were investigated in hearing children varying in age from 3 years 4 months to 5 years 8 months and in deaf children varying in age from 4 years to 6 years 2 months. Three tasks were used: abstract counting, object counting, and creation of sets of a given cardinality. Deaf children exhibited age-related lags in their knowledge of the number sequence; they made different errors from those of hearing children, reflecting the rule-bound nature of sign language. Remarkably, their performance in object counting and creating sets of given cardinality was similar to that of hearing children who had a longer sequence number string, indicating a better use of counting than predicted by their knowledge of the linguistic sequence of numbers.