Effects of Age-of-Acquisition on Proficiency in Polish Sign Language: Insights to the Critical Period Hypothesis.

This study focuses on the relationship between the age of acquisition of Polish Sign Language (PJM) by deaf individuals and their receptive language skills at the phonological, morphological and syntactic levels. Sixty Deaf signers of PJM were recruited into three equal groups (n = 20): (1) a group exposed to PJM from birth from their deaf parents; (2) a group of childhood learners of PJM, who reported learning PJM between 4 and 8 years; (3) a group of adolescent learners of PJM, who reported learning PJM between 9 and 13 years. The PJM Perception and Comprehension Test was used to assess three aspects of language processing: phonological, morphological and syntactic. Participants were asked to decide whether a series of signs and sentences were acceptable in PJM. Results show that the age of PJM acquisition has a significant impact on performance on this task. The earlier deaf people acquire PJM, the more likely they were to distinguish signs and sentences considered permissible and impermissible in PJM by native signers. Native signers had significantly greater accuracy on the phonological, morphological, and syntactic items than either the Childhood or the Adolescent signers. Further, the Childhood signers had significantly greater accuracy than the Adolescent signers on all three parts of the test. Comparing performance on specific structures targeted within each part of the test revealed that multi-channel signs and negative suffixes posed the greatest challenge for Adolescent signers relative to the Native signers. The above results provide evidence from a less-commonly studied signed language that the age of onset of first language acquisition affects ultimate outcomes in language acquisition across all levels of grammatical structure. In addition, this research corroborates prior studies demonstrating that the critical period is independent of language modality. Contrary to a common public health assumption that early exposure to language is less vital to signed than to spoken language development, the results of this study demonstrate that early exposure to a signed language promotes sensitivity to phonological, morphological and syntactic patterns in language.

Expressive and receptive performance with graphic symbol sentences by individuals who use aided communication.

This study explored performance on expressive and receptive graphic symbol tasks and spoken comprehension by individuals who use augmentative and alternative communication (AAC) as well as the relationship of performance with participants' skills and characteristics. Participants were 19 children and youth (aged 5- to 18-years-old) who used aided communication. Four experimental tasks were administered, with either speech or symbols as input (stimuli) and symbols or choice from an array of pictures as output (response). Symbols were not accompanied by written or spoken labels in the tasks. Measures of receptive vocabulary, receptive syntax, memory, and visual cognitive skills as well as information regarding participant characteristics were collected. There were strong relationships among all experimental tasks. Cluster analysis revealed different response patterns that may suggest a progression in expressive and receptive performance with graphic symbol sentences. Individual differences in receptive language, particularly receptive syntax, were related to task performance. The findings suggest that different ways of experiencing symbols, in addition to spoken comprehension of the sentences and receptive spoken language more generally, may contribute to expressive graphic symbol sentences. Performance on receptive symbol tasks may uncover a level of facility with the graphic-symbol modality not observed through expressive symbol use in communicative situations.

Automaticity of lexical access in deaf and hearing bilinguals: Cross-linguistic evidence from the color Stroop task across five languages.

The well-known Stroop interference effect has been instrumental in revealing the highly automated nature of lexical processing as well as providing new insights to the underlying lexical organization of first and second languages within proficient bilinguals. The present cross-linguistic study had two goals: 1) to examine Stroop interference for dynamic signs and printed words in deaf ASL-English bilinguals who report no reliance on speech or audiological aids; 2) to compare Stroop interference effects in several groups of bilinguals whose two languages range from very distinct to very similar in their shared orthographic patterns: ASL-English bilinguals (very distinct), Chinese-English bilinguals (low similarity), Korean-English bilinguals (moderate similarity), and Spanish-English bilinguals (high similarity). Reaction time and accuracy were measured for the Stroop color naming and word reading tasks, for congruent and incongruent color font conditions. Results confirmed strong Stroop interference for both dynamic ASL stimuli and English printed words in deaf bilinguals, with stronger Stroop interference effects in ASL for deaf bilinguals who scored higher in a direct assessment of ASL proficiency. Comparison of the four groups of bilinguals revealed that the same-script bilinguals (Spanish-English bilinguals) exhibited significantly greater Stroop interference effects for color naming than the other three bilingual groups. The results support three conclusions. First, Stroop interference effects are found for both signed and spoken languages. Second, contrary to some claims in the literature about deaf signers who do not use speech being poor readers, deaf bilinguals' lexical processing of both signs and written words is highly automated. Third, cross-language similarity is a critical factor shaping bilinguals' experience of Stroop interference in their two languages. This study represents the first comparison of both deaf and hearing bilinguals on the Stroop task, offering a critical test of theories about bilingual lexical access and cognitive control.

Language development in deaf bilinguals: Deaf middle school students co-activate written English and American Sign Language during lexical processing.

Bilinguals, both hearing and deaf, activate multiple languages simultaneously even in contexts that require only one language. To date, the point in development at which bilingual signers experience cross-language activation of a signed and a spoken language remains unknown. We investigated the processing of written words by ASL-English bilingual deaf middle school students. Deaf bilinguals were faster to respond to English word pairs with phonologically related translations in ASL than to English word pairs with unrelated translations, but no difference was found for hearing controls with no knowledge of ASL. The results indicate that co-activation of signs and written words is not the outcome of years of bilingual experience, but instead characterizes bilingual language development.

Expressive and receptive use of speech and graphic symbols by typically developing children: What skills contribute to performance on structured sentence-level tasks?

PURPOSE: To explore expressive and receptive use of speech and graphic symbols and relationships with linguistic and cognitive skills in children with typical development. METHOD: Participants were 82 children with typical development (4 to 9 years). Measures of memory, visual analysis skills, and receptive language were used, along with five experimental tasks with speech or symbols as input (stimulus) or output (response), using single clause and compound clause stimuli. Cluster analysis grouped participants with similar performances patterns, who were then compared on linguistic and cognitive skill measures. RESULT: The lowest performing group sometimes accurately interpreted graphic symbol utterances that were visible during responding. The mid-performing group was stronger on expressive than receptive symbol utterances when the model did not remain visible. The highest group was comparable on expressive and receptive symbol tasks, but nonetheless stronger with spoken utterances. Relationships of linguistic and cognitive skills with task performance differed across the clusters. CONCLUSION: The findings help clarify the input-output modality asymmetry in graphic symbol communication. Spoken language proficiency does not directly transfer to sentence-level expressive and receptive graphic symbol use. Exploring potentially challenging sentence-level phenomena is important. Research is warranted to explore developmental progressions and potential clinical applications more systematically.

How Bilingualism Contributes to Healthy Development in Deaf Children: A Public Health Perspective.

The aim of this article is to increase awareness of language practices in the deaf community that affect communication needs and health outcomes, focusing particularly on the prevalence of bilingualism among deaf adults. Language deprivation and poor health outcomes in the deaf population are risks that cannot be addressed solely by hearing intervention. We propose that bilingualism acts as a protective measure to minimize the health risks faced by deaf individuals. Provision of culturally and linguistically appropriate services to deaf stakeholders, and particularly hearing families of deaf children, requires familiarity with the developmental and social ramifications of bilingualism.

What is the Source of Bilingual Cross-Language Activation in Deaf Bilinguals?

When deaf bilinguals are asked to make semantic similarity judgments of two written words, their responses are influenced by the sublexical relationship of the signed language translations of the target words. This study investigated whether the observed effects of American Sign Language (ASL) activation on English print depend on (a) an overlap in syllabic structure of the signed translations or (b) on initialization, an effect of contact between ASL and English that has resulted in a direct representation of English orthographic features in ASL sublexical form. Results demonstrate that neither of these conditions is required or enhances effects of cross-language activation. The experimental outcomes indicate that deaf bilinguals discover the optimal mapping between their two languages in a manner that is not constrained by privileged sublexical associations.

The time course of cross-language activation in deaf ASL-English bilinguals.

What is the time course of cross-language activation in deaf sign-print bilinguals? Prior studies demonstrating cross-language activation in deaf bilinguals used paradigms that would allow strategic or conscious translation. This study investigates whether cross-language activation can be eliminated by reducing the time available for lexical processing. Deaf ASL-English bilinguals and hearing English monolinguals viewed pairs of English words and judged their semantic similarity. Half of the stimuli had phonologically related translations in ASL, but participants saw only English words. We replicated prior findings of cross-language activation despite the introduction of a much faster rate of presentation. Further, the deaf bilinguals were as fast or faster than hearing monolinguals despite the fact that the task was in their second language. The results allow us to rule out the possibility that deaf ASL-English bilinguals only activate ASL phonological forms when given ample time for strategic or conscious translation across their two languages.

Bilingual deaf readers' use of semantic and syntactic cues in the processing of English relative clauses.

Eye fixation measures were used to examine English relative clause processing by adult ASL-English bilingual deaf readers. Participants processed subject relative clauses faster than object relative clauses, but expected animacy cues eliminated processing difficulty in object relative clauses. This brings into question previous claims that deaf readers' sentence processing strategies are qualitatively different from those of hearing English native speakers. Measures of English comprehension predicted reading speed, but not differences in syntactic processing. However, a trend for ASL self-ratings to predict the ability to handle syntactic complexity approached significance. Results suggest a need to explore how objective ASL proficiency measures might provide insights into deaf readers' ability to exploit syntactic cues in English.

Effects of SES on literacy development of deaf signing bilinguals.

Research on spoken-language monolinguals and bilinguals has shown that socioeconomic status significantly affects literacy outcomes. One explanation for this effect is that children in higher-SES homes have better oral proficiency in the language of literacy instruction (Hoff, 2013; Zhang et al., 2013). American Sign Language-English deaf bilingual children exhibit a unique profile because they achieve L2 literacy without prior development of spoken L2 proficiency. This provides an opportunity to evaluate the role of SES in literacy development without the confounding effect of the influence of spoken-language proficiency. The present study evaluated effects of SES and ASL proficiency on 135 deaf signing bilinguals' English reading proficiency. Although SES and ASL proficiency were not correlated in this sample, both factors were significant predictors of reading proficiency. The implications of these findings for educational reform in schools with deaf students are discussed.

Sensitivity to verb bias in American sign language-English bilinguals.

Native speakers of English are sensitive to the likelihood that a verb will appear in a specific subcategorization frame, known as verb bias. Readers rely on verb bias to help them resolve temporary ambiguity in sentence comprehension. We investigate whether deaf sign-print bilinguals who have acquired English syntactic knowledge primarily through print exposure show sensitivity to English verb biases in both production and comprehension. We first elicited sentence continuations for 100 English verbs as an offline production measure of sensitivity to verb bias. We then collected eye movement records to examine whether deaf bilinguals' online parsing decisions are influenced by English verb bias. The results indicate that exposure to a second language primarily via print is sufficient to influence use of implicit frequency-based characteristics of a language in production and also to inform parsing decisions in comprehension for some, but not all, verbs.

An investigation of developmental changes in interpretation and construction of graphic AAC symbol sequences through systematic combination of input and output modalities.

While research on spoken language has a long tradition of studying and contrasting language production and comprehension, the study of graphic symbol communication has focused more on production than comprehension. As a result, the relationships between the ability to construct and to interpret graphic symbol sequences are not well understood. This study explored the use of graphic symbol sequences in children without disabilities aged 3;0 to 6;11 (years; months) (n=111). Children took part in nine tasks that systematically varied input and output modalities (speech, action, and graphic symbols). Results show that in 3- and 4-year-olds, attributing meaning to a sequence of symbols was particularly difficult even when the children knew the meaning of each symbol in the sequence. Similarly, while even 3- and 4-year-olds could produce a graphic symbol sequence following a model, transposing a spoken sentence into a graphic sequence was more difficult for them. Representing an action with graphic symbols was difficult even for 5-year-olds. Finally, the ability to comprehend graphic-symbol sequences preceded the ability to produce them. These developmental patterns, as well as memory-related variables, should be taken into account in choosing intervention strategies with young children who use AAC.

Bilingual word recognition in deaf and hearing signers: Effects of proficiency and language dominance on cross-language activation.

Recent evidence demonstrates that American Sign Language signs are active during print word recognition in deaf bilinguals who are highly proficient in both ASL and English. In the present study, we investigate whether signs are active during print word recognition in two groups of unbalanced bilinguals: deaf ASL-dominant and hearing English-dominant bilinguals. Participants judged the semantic relatedness of word pairs in English. Critically, a subset of both the semantically related and unrelated English word pairs had phonologically related translations in ASL, but participants were never shown any ASL signs during the experiment. Deaf ASL-dominant bilinguals (Experiment 1) were faster when semantically related English word pairs had similar form translations in ASL, but slower when semantically unrelated words had similar form translations in ASL, indicating that ASL signs are engaged during English print word recognition in these ASL-dominant signers. Hearing English-dominant bilinguals (Experiment 2) were also slower to respond to semantically unrelated English word pairs with similar form translations in ASL, but no facilitation effects were observed in this population. The results provide evidence that the interactive nature of lexical processing in bilinguals is impervious to language modality.

Deaf readers' response to syntactic complexity: evidence from self-paced reading.

This study was designed to determine the feasibility of using self-paced reading methods to study deaf readers and to assess how deaf readers respond to two syntactic manipulations. Three groups of participants read the test sentences: deaf readers, hearing monolingual English readers, and hearing bilingual readers whose second language was English. In Experiment 1, the participants read sentences containing subject-relative or object-relative clauses. The test sentences contained semantic information that would influence online processing outcomes (Traxler, Morris, & Seely Journal of Memory and Language 47: 69-90, 2002; Traxler, Williams, Blozis, & Morris Journal of Memory and Language 53: 204-224, 2005). All of the participant groups had greater difficulty processing sentences containing object-relative clauses. This difficulty was reduced when helpful semantic cues were present. In Experiment 2, participants read active-voice and passive-voice sentences. The sentences were processed similarly by all three groups. Comprehension accuracy was higher in hearing readers than in deaf readers. Within deaf readers, native signers read the sentences faster and comprehended them to a higher degree than did nonnative signers. These results indicate that self-paced reading is a useful method for studying sentence interpretation among deaf readers.

Sign Perception and Recognition in Non-Native Signers of ASL.

Past research has established that delayed first language exposure is associated with comprehension difficulties in non-native signers of American Sign Language (ASL) relative to native signers. The goal of the current study was to investigate potential explanations of this disparity: do non-native signers have difficulty with all aspects of comprehension, or are their comprehension difficulties restricted to some aspects of processing? We compared the performance of deaf non-native, hearing L2, and deaf native signers on a handshape and location monitoring and a sign recognition task. The results indicate that deaf non-native signers are as rapid and accurate on the monitoring task as native signers, with differences in the pattern of relative performance across handshape and location parameters. By contrast, non-native signers differ significantly from native signers during sign recognition. Hearing L2 signers, who performed almost as well as the two groups of deaf signers on the monitoring task, resembled the deaf native signers more than the deaf non-native signers on the sign recognition task. The combined results indicate that delayed exposure to a signed language leads to an overreliance on handshape during sign recognition.

When deaf signers read English: do written words activate their sign translations?

Deaf bilinguals for whom American Sign Language (ASL) is the first language and English is the second language judged the semantic relatedness of word pairs in English. Critically, a subset of both the semantically related and unrelated word pairs were selected such that the translations of the two English words also had related forms in ASL. Word pairs that were semantically related were judged more quickly when the form of the ASL translation was also similar whereas word pairs that were semantically unrelated were judged more slowly when the form of the ASL translation was similar. A control group of hearing bilinguals without any knowledge of ASL produced an entirely different pattern of results. Taken together, these results constitute the first demonstration that deaf readers activate the ASL translations of written words under conditions in which the translation is neither present perceptually nor required to perform the task.

Strategies in construction and interpretation of graphic-symbol sequences by individuals who use AAC systems.

Given the frequent use of graphic symbols in augmentative and alternative communication (AAC) systems, some individuals who use AAC may have greater familiarity with constructing graphic-symbol sequences than do speaking individuals without disabilities. Whether this increased familiarity has an impact on the interpretation of such sequences or on the relationship between construction and interpretation is fundamental to our understanding of the mechanisms underlying communication using graphic symbols. In this study, individuals who use graphic-symbol AAC systems were asked to construct and interpret graphic-symbol sequences representing the same target content (simple and complex propositions). The majority of participants used stable response patterns on both tasks; a minority were inconsistent on both tasks. Asymmetrical patterns (stable on one task but not the other) were rare, suggesting that neither channel (construction or interpretation) preceded the other, in contrast to earlier findings with participants without disabilities (i.e., novice users of graphic symbols). Furthermore, there were differences between stable and less stable responders on measures of syntactic comprehension and cognitive level but not on chronological age, receptive vocabulary, or AAC system characteristics and length of use.

The role of word order in the interpretation of canonical and non-canonical graphic symbol utterances: A developmental study.

Graphic symbols are often used to represent words in Augmentative and Alternative Communication systems. Previous findings suggest that different processes operate when using graphic symbols and when using speech. This study assessed the ability of native speakers of French with no communication disorders from four age groups to interpret graphic-symbol sequences of varying length and canonicity. Results reveal that, as they get older, participants show an increase in their capacity to interpret graphic-symbol sequences. Constituent order played an important role in the interpretation of the sequences. However, the specific word-order strategies used varied depending on the age group and the type of sequence presented.

Effects of language experience on the perception of American Sign Language.

Perception of American Sign Language (ASL) handshape and place of articulation parameters was investigated in three groups of signers: deaf native signers, deaf non-native signers who acquired ASL between the ages of 10 and 18, and hearing non-native signers who acquired ASL as a second language between the ages of 10 and 26. Participants were asked to identify and discriminate dynamic synthetic signs on forced choice identification and similarity judgement tasks. No differences were found in identification performance, but there were effects of language experience on discrimination of the handshape stimuli. Participants were significantly less likely to discriminate handshape stimuli drawn from the region of the category prototype than stimuli that were peripheral to the category or that straddled a category boundary. This pattern was significant for both groups of deaf signers, but was more pronounced for the native signers. The hearing L2 signers exhibited a similar pattern of discrimination, but results did not reach significance. An effect of category structure on the discrimination of place of articulation stimuli was also found, but it did not interact with language background. We conclude that early experience with a signed language magnifies the influence of category prototypes on the perceptual processing of handshape primes, leading to differences in the distribution of attentional resources between native and non-native signers during language comprehension.