Visual constructive and visual-motor skills in deaf native signers

Visual constructive and visual-motor skills in the deaf population were investigated by comparing performance of deaf native signers (n=20) to that of hearing nonsigners (n=20) on the Beery-Buktenica Developmental Test of Visual-Motor Integration, Rey-Osterrieth Complex Figure Test, Wechsler Memory Scale Visual Reproduction subtest, and Stanford-Binet Intelligence Scale Paper Folding and Cutting subtest. Deaf signers were found to perform similarly to hearing controls, suggesting that these tests are valid assessment instruments to use with deaf individuals.     

Visual spatial representation in mathematical problem solving by deaf and hearing students

This research examined the use of visual-spatial representation by deaf and hearing students while solving mathematical problems. The connection between spatial skills and success in mathematics performance has long been established in the literature. This study examined the distinction between visual-spatial "schematic" representations that encode the spatial relations described in a problem versus visual-spatial "pictorial" representations that encode only the visual appearance of the objects described in a problem. A total of 305 hearing (n = 156) and deaf (n = 149) participants from middle school, high school, and college participated in this study. At all educational levels, the hearing students performed significantly better in solving the mathematical problems compared to their deaf peers. Although the deaf baccalaureate students exhibited the highest performance of all the deaf participants, they only performed as well as the hearing middle school students who were the lowest scoring hearing group. Deaf students remained flat in their performance on the mathematical problem-solving task from middle school through the college associate degree level. The analysis of the students' problem representations showed that the hearing participants utilized visual-spatial schematic representation to a greater extent than did the deaf participants. However, the use of visual-spatial schematic representations was a stronger positive predictor of mathematical problem-solving performance for the deaf students. When deaf students' problem representation focused simply on the visual-spatial pictorial or iconic aspects of the mathematical problems, there was a negative predictive relationship with their problem-solving performance. On two measures of visual-spatial abilities, the hearing students in high school and college performed significantly better than their deaf peers.     

Differences in the use of American Sign Language morphology by deaf children: implications for parents and teachers

Newport (1988) has noted differences in how American Sign Language (ASL) is used by the following three groups of deaf adults: those with deaf parents (native signers); those, with hearing parents, who learned ASL upon entering school at age 5 years (early signers); and those who learned to sign after puberty (late signers). The present study extends this research to children by investigating the use of morphological inflections in ASL by native and early signers. Thirty deaf children between ages 3 and 9 years were asked to sign a story in ASL. The videotaped stories were analyzed for morphological and contextual complexity. Qualitative differences were found between native and early signers on measures relating to the aspectual complexity of signs but not on measures relating to the complexity of the utterance. Implications of these differences are discussed in terms of communication at home and ASL use in the classroom.     

Studies of neural processing in deaf signers: toward a neurocognitive model of language processing in the deaf

The ability to comprehend and produce language stands as a defining characteristic of human cognition and enables the transfer of knowledge and culture within human society. A proper characterization of the human capacity for language is required for the development of interventions that may be used to assist those individuals who have failed to achieve, or who have lost competence in, language behaviors. For signed languages, models of competent language use are lacking. This lack of knowledge hampers the development of effective assessment measures for deaf children who may be experiencing learning problems beyond those confronting the normal deaf child. I discuss two research avenues that have begun to provide a window into the neural systems involved in sign language processing: studies of language disruptions in adult deaf signers who have suffered brain injury, and studies of functional brain imaging in normal deaf signers. This research provides a basis for the development of a comprehensive neurocognitive model of sign language processing.     

Numerical Magnitude Representations and Individual Differences in Children's Arithmetic Strategy Use

Against the background of neuroimaging studies on how the brain processes numbers, there is now converging evidence that numerical magnitude representations are crucial for successful mathematics achievement. One major drawback of this research is that it mainly investigated mathematics performance as measured through general standardized achievement tests. We extended this research by investigating the association between numerical magnitude representations and children's strategy use during single‐digit arithmetic. Our findings reveal that children's symbolic but not nonsymbolic numerical magnitude processing skills are associated with individual differences in arithmetic. Children with better access to magnitude representations from symbolic digits retrieve more facts from their memory and are faster in executing fact retrieval as well as procedural strategies. These associations remain even when intellectual ability, digit naming, and general mathematics achievement are additionally controlled for. All this indicates that particularly the access to numerical meaning from Arabic symbols is key for children's arithmetic strategy development, which suggests that educators and remedial teachers should focus on connecting Arabic symbols to the quantities they represent.     

Comparing action gestures and classifier verbs of motion: evidence from Australian Sign Language, Taiwan Sign Language, and nonsigners' gestures without speech

Recent research into signed languages indicates that signs may share some properties with gesture, especially in the use of space in classifier constructions. A prediction of this proposal is that there will be similarities in the representation of motion events by sign-naive gesturers and by native signers of unrelated signed languages. This prediction is tested for deaf native signers of Australian Sign Language (Auslan), deaf signers of Taiwan Sign Language (TSL), and hearing nonsigners using the Verbs of Motion Production task from the Test Battery for American Sign Language (ASL) Morphology and Syntax. Results indicate that differences between the responses of nonsigners, Auslan signers, and TSL signers and the expected ASL responses are greatest with handshape units; movement and location units appear to be very similar. Although not definitive, these data are consistent with the claim that classifier constructions are blends of linguistic and gestural elements.     

Siblings and theory of mind in deaf native signing children

We report a study designed to examine the basis of "theory of mind" (ToM) reasoning in deaf children who are native signers of British Sign Language. The participants were 20 native signers (aged 4-8 years) and their siblings. The children were given a measure of the quality of sibling relations together with a referential communication test concerning physical representations of objects and people. Sibling quality as perceived by siblings predicted children's ToM scores over and above age and referential communication. We conclude that the process of ToM understanding is linked to positive sibling relations that may permit access to knowledge about the inner worlds of beliefs and other mental states.     

Signposts to development: theory of mind in deaf children

Possession of a "theory of mind" (ToM)--as demonstrated by an understanding of the false beliefs of others--is fundamental in children's cognitive development. A key question for debate concerns the effect of language input on ToM. In this respect, comparisons of deaf native-signing children who are raised by deaf signing parents with deaf late-signing children who are raised by hearing parents provide a critical test. This article reports on two studies (N = 100 and N = 39) using "thought picture" measures of ToM that minimize verbal task-performance requirements. These studies demonstrated that even when factors such as syntax ability, mental age in spatial ability, and executive functioning were considered, deaf late signers still showed deficits in ToM understanding relative to deaf native signers or hearing controls. Even though the native signers were significantly younger than a sample of late signers matched for spatial mental age and scores on a test of receptive sign language ability, native signers outperformed late signers on pictorial ToM tasks. The results are discussed in terms of access to conversation and extralinguistic influences on development such as the presence of sibling relationships, and suggest that the expression of a ToM is the end result of social understanding mediated by early conversational experience.     

感觉经验缺失对视力、听力障碍学生概念表征的影响

通过概念特征自由联想实验,比较了视力、听力障碍学生和普通学生的具体事物概念表征的差异。结果表明:(1)与普通学生相比,视力、听力障碍学生联想的特征数量少,分布分散。(2)视力、听力障碍学生的概念表征受感知觉经验缺失的影响,概念表征具有明显的通道差异。聋生的听觉通道的概念特征显著少于普通学生,盲生的触觉通道的概念特征显著多于普通学生和聋生。(3)在感觉代偿和语言学习的帮助下,视力、听力障碍学生能够形成对缺失感觉通道信息的概念的表征。     

Subitizing, magnitude representation, and magnitude retrieval in deaf and hearing adults

This study examines basic number processing (subitizing, automaticity, and magnitude representation) as the possible underpinning of mathematical difficulties often evidenced in deaf adults. Hearing and deaf participants completed tasks to assess the automaticity with which magnitude information was activated and retrieved from long-term memory (using a Stroop-like paradigm to assess congruity effects), the representational format of magnitude information (by analysis of distance and Spatial Numerical Association of Response Codes effects), and the ability to rapidly enumerate small sets (subitizing). Both groups showed distance effects taken to indicate the use of a visual-spatial analog number line representing approximate quantity. Furthermore, both groups showed similar patterns of performance on the subitizing tasks and showed similar amounts of interference in an analysis of congruity effects. This is taken as evidence against the notion that idiosyncratic differences in basic number processing account for mathematical difficulties experienced by deaf individuals.     

An investigation of the Stroop effect among deaf signers in English and Japanese: automatic processing or memory retrieval?

Most studies on the Stroop effect (unintentional automatic word processing) have been restricted to English speakers using vocal responses. Little is known about this effect with deaf signers. The study compared Stroop task responses among four different samples: deaf participants from a Japanese-language environment and from an English-language environment; and hearing individuals from Japan and from Australia. Color words were prepared in both English and Japanese and were presented in three conditions: congruent (e.g., the word red printed in red), incongruent (e.g., red printed in blue), and neutral. The magnitude of the effect was greater with the deaf participants than with the hearing participants. The deaf individuals experienced more interference in English than in Japanese.     

Enhanced facial discrimination: effects of experience with American sign language

On-line comprehension of American Sign Language (ASL) requires rapid discrimination of linguistic facial expressions. We hypothesized that ASL signers' experience discriminating linguistic facial expressions might lead to enhanced performance for discriminating among different faces. Five experiments are reported that investigate signers' and non-signers' ability to discriminate human faces photographed under different conditions of orientation and lighting (the Benton Test of Facial Recognition). The results showed that deaf signers performed significantly better than hearing non-signers. Hearing native signers (born to deaf parents) also performed better than hearing nonsigners, suggesting that the enhanced performance of deaf signers is linked to experience with ASL rather than to auditory deprivation. Deaf signers who acquired ASL in early adulthood did not differ from native signers, which suggests that there is no 'critical period' during which signers must be exposed to ASL in order to exhibit enhanced face discrimination abilities. When the faces were inverted, signing and nonsigning groups did not differ in performance. This pattern of results suggests that experience with sign language affects mechanisms specific to face processing and does not produce a general enhancement of visual discrimination. Finally, a similar pattern of results was found with signing and nonsigning children, 6-9 years old. Overall, the results suggest that the brain mechanisms responsible for face processing are somewhat plastic and can be affected by experience. We discuss implications of these results for the relation between language and cognition.     

Phonological representations in deaf children: rethinking the "functional equivalence" hypothesis

The sources of knowledge that individuals use to make similarity judgments between words are thought to tap underlying phonological representations. We examined the effects of perceptual similarity between stimuli on deaf children's ability to make judgments about the phonological similarity between words at 3 levels of linguistic structure (syllable, rhyme, and phoneme). Manipulation of stimulus contrasts (acoustic, visual/orthographic, tactile/motoric) allowed a finer-grained estimate of the sources of knowledge that deaf individuals use to make similarity judgments between words. The results showed that the ability to make syllable-, rhyme-, and phoneme-level judgments was not tied to "phonological" facilitation when these conditions are contrasted. These findings are inconsistent with long-held assumptions of "functional" equivalence between "heard" and "seen" speech in the development of phonological representations in deaf learners. We argue that previous studies reporting evidence for phonological effects in similarity judgments have failed to sufficiently control for alternative sources of sensory information, namely, visual and tactile/motoric.     

Written language abilities in deaf Italians

Written texts produced by 10 Italian deaf native signers in four different writing tasks were analyzed. Data analysis focused on linguistic and orthographic nonstandard forms. The written production of deaf subjects with deaf parents (DD) was compared to the written production in two control groups: a group of 10 hearing subjects with deaf parents (HD) and a group of 10 subjects who have had no contact with deaf people or sign language (HH). The results duplicate findings from previous studies. Deaf subjects display a pattern of selective difficulty with Italian grammatical morphology, especially with free-standing function words. The four different writing tasks used in the present study yield results indicating that text type does influence our assessment of deaf writing abilities. A comparison of the texts written by deaf native signers with those of two hearing groups confirms the view that difficulties in the acquisition of written Italian are best explained by deafness itself, not by the influence of a previously acquired Sign Language, and that the specific difficulties with grammatical morphology displayed by our deaf subjects cannot be attributed solely to their limited experience with written Italian.     

Spelling development in deaf and hearing children: Evidence for use of morpho-phonological regularities in French

This study investigated the processes that deaf school children use for spelling. Hearing and deaf spellers of two age groups spelled three types of words differing in orthographic transparency (Regular, Morphological and Opaque words). In all groups, words that could be spelled on the basis of phoneme-grapheme knowledge (Regular words) were easier than words that could be spelled only on the basis of lexical orthographic information (Opaque words). Words in which spelling can be derived from morphological information were easier than Opaque words for older deaf and hearing subjects but not for younger subjects. In deaf children, use of phoneme-grapheme knowledge seems to develop with age, but only in those individuals who had intelligible speech. The presence of systematic misspellings indicates that the hearing-impaired youngsters rely upon inaccurate speech representations they derived mainly form lip-reading. The findings thus suggest that deaf subjects's spelling is based on an exploitation of the linguistic regularities represented in the French alphabetic orthography, but that this exploitation is limited by the vagueness of their representations of oral language. These findings are discussed in the light of current developmental models of spelling acquisition.     

The performance of young deaf children in spatial and temporal number tasks

Deaf children tend to fall behind in mathematics at school. This problem may be a direct result of particular experiences in the classroom; for example, deaf children may find it hard to follow teachers' presentations of basic, but nevertheless quite abstract, mathematical ideas. Another possibility is that the problem starts before school: They may either be worse than hearing children at early, nonlinguistic number representations, they may be behind in learning the culturally transmitted number string, or both. This may result in deaf children failing to develop informal problem-solving strategies, which prepare most children for the more formal learning of number and arithmetic that they will have to do at school. We compared 3- and 4-year-old deaf and hearing children's ability to remember and to reproduce the number of items in a set of objects. In one condition, we presented all the items together in a spatial array; in another, we presented them one at a time in a temporal sequence. Deaf children performed as well as the hearing children in the temporal tasks, but outperformed their hearing counterparts in the spatial task. These results suggest that preschool deaf children's number representation is at least as advanced as that of hearing children, and that they are actually better than hearing children at representing the number of objects in spatial arrays. We conclude that deaf children's difficulties with mathematical learning are not a consequence of a delay in number representation. We also conclude that deaf children should benefit from mathematical instruction that emphasizes spatial representation.     

The use of visual feedback during signing: evidence from signers with impaired vision

The role of visual feedback during the production of American Sign Language was investigated by comparing the size of signing space during conversations and narrative monologues for normally sighted signers, signers with tunnel vision due to Usher syndrome, and functionally blind signers. The interlocutor for all groups was a normally sighted deaf person. Signers with tunnel vision produced a greater proportion of signs near the face than blind and normally sighted signers, who did not differ from each other. Both groups of visually impaired signers produced signs within a smaller signing space for conversations than for monologues, but we hypothesize that they did so for different reasons. Signers with tunnel vision may align their signing space with that of their interlocutor. In contrast, blind signers may enhance proprioceptive feedback by producing signs within an enlarged signing space for monologues, which do not require switching between tactile and visual signing. Overall, we hypothesize that signers use visual feedback to phonetically calibrate the dimensions of signing space, rather than to monitor language output.     

Modality of language shapes working memory: evidence from digit span and spatial span in ASL signers

Deaf children who are native users of American Sign Language (ASL) and hearing children who are native English speakers performed three working memory tasks. Results indicate that language modality shapes the architecture of working memory. Digit span with forward and backward report, performed by each group in their native language, suggests that the language rehearsal mechanisms for spoken language and for sign language differ in their processing constraints. Unlike hearing children, deaf children who are native signers of ASL were as good at backward recall of digits as at forward recall, suggesting that serial order information for ASL is stored in a form that does not have a preferred directionality. Data from a group of deaf children who were not native signers of ASL rule out explanations in terms of a floor effect or a nonlinguistic visual strategy. Further, deaf children who were native signers outperformed hearing children on a nonlinguistic spatial memory task, suggesting that language expertise in a particular modality exerts an influence on nonlinguistic working memory within that modality. Thus, language modality has consequences for the structure of working memory, both within and outside the linguistic domain.     

How Do Profoundly Deaf Children Learn to Read?

Reading requires two related, but separable, capabilities: (1) familiarity with a language, and (2) understanding the mapping between that language and the printed word (Chamberlain & Mayberry, 2000; Hoover & Gough, 1990). Children who are profoundly deaf are disadvantaged on both counts. Not surprisingly, then, reading is difficult for profoundly deaf children. But some deaf children do manage to read fluently. How? Are they simply the smartest of the crop, or do they have some strategy, or circumstance, that facilitates linking the written code with language? A priori one might guess that knowing American Sign Language (ASL) would interfere with learning to read English simply because ASL does not map in any systematic way onto English. However, recent research has suggested that individuals with good signing skills are not worse, and may even be better, readers than individuals with poor signing skills (Chamberlain & Mayberry, 2000). Thus, knowing a language (even if it is not the language captured in print) appears to facilitate learning to read. Nonetheless, skill in signing does not guarantee skill in reading—reading must be taught. The next frontier for reading research in deaf education is to understand how deaf readers map their knowledge of sign language onto print, and how instruction can best be used to turn signers into readers.     

Homophone effects in deaf readers: evidence from lexical decision

The current study examined the nature of deaf readers’ phonological processing during online word recognition, and how this compares to similar effects in hearing individuals. Unlike many previous studies on phonological activation, we examined whether deaf readers activated phonological representations for words as opposed to pseudohomophones. Both hearing and deaf adults performed lexical decisions on homophones and control words in the context of either pseudoword foils (e.g., CLANE) or pseudohomophone foils (e.g., BRANE). As expected, hearing readers responded more slowly to homophones than to control words in both non-word contexts, reflecting phonological activation during reading. In contrast, deaf readers responded more slowly to homophones than to control words in the pseudohomophone foil context, but not in the pseudoword foil context. This finding suggests that deaf readers are able to activate phonological representations; however the nature of these representations appears to be more coarse-grained in deaf readers.