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.     

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.     

The effect of irrelevant visual input on working memory for sign language

We report results showing that working memory for American Sign Language (ASL) is sensitive to irrelevant signed input (and other structured visual input) in a manner similar to the effects of irrelevant auditory input on working memory for speech. Deaf signers were disrupted on serial recall of lists of ASL signs when either pseudosigns or moving shapes were presented during a retention interval. Hearing subjects asked to recall lists of printed English words did not show disruption under the same interference conditions. The results favor models that hypothesize modality-specific representations of language within working memory, as opposed to amodal representations. The results further indicate that working memory for sign language involves visual or quasi-visual representations, suggesting parallels to visuospatial working memory.     

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.     

Working memory for sign language: a window into the architecture of the working memory system

Traditionally, working memory has been divided into two major domains: verbal and visuo-spatial. The verbal domain of working memory can be characterized either by its relationship to language or by its grounding in auditory processing. Because of this ambiguity, languages that are not auditory and vocal (i.e., signed languages) pose a challenge to this conception of working memory. We describe several experiments with deaf users of American Sign Language (ASL) that explore the extent to which the architecture of working memory is determined by the constraints of auditory and visual processing and the extent to which it is determined by the characteristics of language. Various working memory effects were investigated: phonological similarity, word length, and articulatory suppression. The pattern of evidence strongly supports the existence of a sign-based 'rehearsal loop' mechanism parallel to the speech-based rehearsal loop. However, we also discuss evidence pointing to differences between the speech loop and the sign loop from forward and backward digit span tasks with deaf and hearing subjects. Despite their similarities based on linguistic properties, the speech loop and the sign loop appear to diverge due to the differing processing demands of audition and vision. Overall, the results suggest that the architecture of working memory is shaped both by the properties of language structure and by the constraints imposed by sensorimotor modality.     

Language and theory of mind: a study of deaf children

Theory-of-mind (ToM) abilities were studied in 176 deaf children aged 3 years 11 months to 8 years 3 months who use either American Sign Language (ASL) or oral English, with hearing parents or deaf parents. A battery of tasks tapping understanding of false belief and knowledge state and language skills, ASL or English, was given to each child. There was a significant delay on ToM tasks in deaf children of hearing parents, who typically demonstrate language delays, regardless of whether they used spoken English or ASL. In contrast, deaf children from deaf families performed identically to same-aged hearing controls (N=42). Both vocabulary and understanding syntactic complements were significant independent predictors of success on verbal and low-verbal ToM tasks.     

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.     

Face processing by deaf ASL signers: evidence for expertise in distinguished local features

Several previous studies have shown that ASL signers are 'experts' on at least one test of face processing: the Benton Test of Face Recognition, a discrimination task that requires subjects to select a target face from a set of faces shown in profile and/or in shadow. The experiments reported here were designed to discover why ASL signers have superior skill as measured by this test and to investigate whether enhanced performance extends to other aspects of face processing. Experiment 1 indicated that the enhancement in face-processing skills does not extend to recognition of faces from memory. Experiment 2 revealed that deaf and hearing subjects do not differ in their gestalt face-processing ability; they perform similarly on a closure test of face perception. Finally, experiment 3 suggested that ASL signers do exhibit a superior ability to detect subtle differences in facial features. This superior performance may be linked both to experience discriminating ASL grammatical facial expression and to experience with lipreading. We conclude that only specific aspects of face processing are enhanced in deaf signers: those skills relevant to detecting local feature configurations that must be generalized over individual faces.     

The hands have it: number representations in adult deaf signers

This study examines a wide range of numerical representations (i.e., quantity, knowledge of multiplication facts, and use of parity information) in adult deaf signers. We introduce a modified version of the number bisection task, with sequential stimulus presentation, which allows for a systematic examination of mathematical skills in deaf individuals in different modalities (number signs in streaming video vs. Arabic digit displays). Reaction times and accuracy measures indicated that deaf signers make use of several representations simultaneously when bisecting number triplets, paralleling earlier findings in hearing individuals. Furthermore, some differences were obtained between the 2 display modalities, with effects being less prominent in the Arabic digit mode, suggesting that mathematical abilities in deaf signers should be assessed in their native sign language.     

How the medical professionals impact ASL and English families’ language planning policy

This article explores the journey of eight hearing families of bimodal-bilingual deaf children as they navigate the decision-making process reflecting their beliefs and values about American Sign Language (ASL) and English through their family language policy framework. The resources offered to families with deaf children often reflect a medical view, rather than a cultural perspective of being deaf. Because medical professionals, educators, and specialists who work with deaf and hard-of-hearing children have a strong influence on family members’ opinions, beliefs, and attitudes about being deaf, it is even more crucial to correct misconceptions about ASL and empower families to develop a family language policy that is inclusive of their deaf and hard-of-hearing children. This article informs researchers, teachers, and other professionals about the potential benefits and challenges of supporting the families’ ASL and English language planning policy.     

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.     

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.     

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.     

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.     

Language codes and sense-making among deaf schoolchildren

There are at least two languages (American Sign Language [ASL], English) and three modalities (sign, speech, print) in most deaf individuals' lives. Mixing of ASL and English in utterances of deaf adults has been described in various ways (pidgins, diglossia, language contact, bilingualism), but children's mixing usually is treated as the 'fault' of poor input language. Alternatively, how might language mixing serve their communication goals? This article describes code variations and adaptations to particular situations. Deaf children were seen to exhibit a wide variety of linguistic structures mixing ASL, English, Spanish, signing, and speaking. Formal lessons supported a recoding of English print as sign and speech, but the children who communicated English speech were the two who could hear speech. The children who communicated ASL were those who had deaf parents communicating ASL or who identified with deaf houseparents communicating ASL. Most language produced by the teacher and children in this study was mixed in code and mode. While some mixing was related to acquisition and proficiency, mixing, a strategy of many deaf individuals, uniquely adapts linguistic resources to communication needs. Investigating deaf children's language by comparing it to standard English or ASL overlooks the rich strategies of mixing that are central to their communication experience.     

A study of the relationship between American sign language and English literacy

This article presents the findings of a study of the relationship between American Sign Language (ASL) skills and English literacy among 160 deaf children. Using a specially designed test of ASL to determine three levels of ASL ability, we found that deaf children who attained the higher two levels significantly outperformed children in the lowest ASL ability level in English literacy, regardless of age and IQ. Furthermore, although deaf children with deaf mothers outperformed deaf children of hearing mothers in both ASL and English literacy, when ASL level was held constant, there was no difference between these two groups, except in the lowest level of ASL ability. The implication of this research is straightforward and powerful: Deaf children's learning of English appears to benefit from the acquisition of even a moderate fluency in ASL.     

The role of spoken and sign languages in the retention of written words by prelingually deafened native signers

The purpose of this study was to determine the nature and efficiency of the strategies used by prelingually deafened native signers for the temporary retention of written words with reference to a primary language-coding hypothesis (M. A. Shand, 1982). For the gathering of the data, participants were shown lists of serially presented written target words that they were asked to recognize according to their presentation order from within word pools that contained different types of code-specific distracter words. Three performance dimensions were examined: (a) false recognition of target words, (b) correct recognition of target words, and (c) retention of target word presentation order. Participants were prelingually deafened native signers (n=11, average grade level=8.18 [1.17]) and a hearing control group (n=25, average grade level=9.00 [0.76]). Findings from the analysis of the nature of false recognition and the number of correctly recognized words show convincingly that formationally similar distracter words interfered with the memory performance of the native signers and phonologically similar distracter words with that of the hearing control group. It was concluded that the participants decoded written words into a code reflecting their primary language experience for their temporary retention in working memory.     

The use of repair strategies: bilingual deaf children using sign language and spoken language

The language effects on repair strategies employed by 7 bilingual deaf children (native signers who also used spoken language) was examined. During two sessions--one conducted in sign language and the other in spoken language--each child described a picture. The examiner stopped the child twice to request clarification. The children's responses to the requests were coded into seven repair strategies. Results indicated that language mode significantly influenced repair strategy behavior: In sign language, the children used a greater frequency, variety, and level of strategies. The position of the clarification request also had an effect: Later in the sequence, the children used more advanced strategies. It was assumed that these native signers evidenced a higher language level in sign, which allowed them to use more advanced communicational strategies in sign than in spoken language. This performance gap should be considered in intervention.     

Using online glossing lessons for accelerated instruction in ASL for preservice deaf education majors

Teachers of deaf and hard of hearing students must serve as language models for their students. However, preservice deaf education teachers typically have at most only four semesters of American Sign Language (ASL) training. How can their limited ASL instructional time be used to increase their proficiency? Studies involving deaf and hard of hearing students have revealed that glosses (written equivalents of ASL sentences) can serve as "bridges" between ASL and English. The study investigated whether glossing instruction can facilitate hearing students' learning of ASL. A Web site was developed in which ASL glossing rules were explained and glossing exercises provided. Posttest scores showed the experimental group improving from 39% to 71% on ASL grammar knowledge. These findings indicate that online glossing lessons may provide the means to obtain ASL skills more readily, thus preparing deaf education teachers to serve as ASL language models.     

Deaf children's use of phonological coding: evidence from reading, spelling, and working memory

Two groups of deaf children, aged 8 and 14 years, were presented with a number of tasks designed to assess their reliance on phonological coding. Their performance was compared with that of hearing children of the same chronological age (CA) and reading age (RA). Performance on the first task, short-term recall of pictures, showed that the deaf children's spans were comparable to those of RA controls but lower than CA controls. For the older deaf children, short-term memory span predicted reading ability. There was no clear evidence that the deaf children were using phonological coding in short-term memory when recall of dissimilar items was compared with recall of items with similarly sounding names. In the second task, which assessed orthographic awareness, performance of the deaf children was similar to that of RA controls although scores predicted reading level for the deaf children but not the hearing. The final task was a picture spelling test in which there were marked differences between the deaf and hearing children, most notably in the number of spelling refusals (which was higher for the deaf children in the older group than their RA controls) and the percentage of phonetic errors (which was considerably lower for both groups of deaf children than for any of the hearing controls). Overall these results provide support for the view that deaf children place little reliance on phonological coding.