The rhyming skills of deaf children educated with phonetically augmented speechreading

Exposure to Canadian French Cued Speech Improves Consonant Articulation in Children With Cochlear Implants: Acoustic and Articulatory Data

PURPOSE

One of the strategies that can be used to support speech communication in deaf children is cued speech, a visual code in which manual gestures are used as additional phonological information to supplement the acoustic and labial speech information. Cued speech has been shown to improve speech perception and phonological skills. This exploratory study aims to assess whether and how cued speech reading proficiency may also have a beneficial effect on the acoustic and articulatory correlates of consonant production in children.

METHOD

Eight children with cochlear implants (from 5 to 11 years of age) and with different receptive proficiency in Canadian French Cued Speech (three children with low receptive proficiency vs. five children with high receptive proficiency) are compared to 10 children with typical hearing (from 4 to 11 years of age) on their production of stop and fricative consonants. Articulation was assessed with ultrasound measurements.

RESULTS

The preliminary results reveal that cued speech proficiency seems to sustain the development of speech production in children with cochlear implants and to improve their articulatory gestures, particularly for the place contrast in stops as well as fricatives.

CONCLUSION

This work highlights the importance of studying objective data and comparing acoustic and articulatory measurements to better characterize speech production in children.

Speech rehabilitation in children with cochlear implants using a multisensory (French Cued Speech) or a hearing-focused (Auditory Verbal Therapy) approach

Introduction

Early exposure to a rich linguistic environment is essential as soon as the diagnosis of deafness is made. Cochlear implantation (CI) allows children to have access to speech perception in their early years. However, it provides only partial acoustic information, which can lead to difficulties in perceiving some phonetic contrasts. This study investigates the contribution of two spoken speech and language rehabilitation approaches to speech perception in children with CI using a lexicality judgment task from the EULALIES battery. Auditory Verbal Therapy (AVT) is an early intervention program that relies on auditory learning to enhance hearing skills in deaf children with CI. French Cued Speech, also called Cued French (CF), is a multisensory communication tool that disambiguates lip reading by adding a manual gesture.

Methods

In this study, 124 children aged from 60 to 140 months were included: 90 children with typical hearing skills (TH), 9 deaf children with CI who had participated in an AVT program (AVT), 6 deaf children with CI with high Cued French reading skills (CF+), and 19 deaf children with CI with low Cued French reading skills (CF-). Speech perception was assessed using sensitivity (d') using both the hit and false alarm rates, as defined in signal-detection theory.

Results

The results show that children with cochlear implants from the CF- and CF+ groups have significantly lower performance compared to children with typical hearing (TH) (p < 0.001 and p = 0.033, respectively). Additionally, children in the AVT group also tended to have lower scores compared to TH children (p = 0.07). However, exposition to AVT and CF seems to improve speech perception. The scores of the children in the AVT and CF+ groups are closer to typical scores than those of children in the CF- group, as evidenced by a distance measure.

Discussion

Overall, the findings of this study provide evidence for the effectiveness of these two speech and language rehabilitation approaches, and highlight the importance of using a specific approach in addition to a cochlear implant to improve speech perception in children with cochlear implants.

Factors Affecting the Writing Performance in Hearing and Deaf Children: An Insight into Regularities and Irregularities of the Arabic Orthographic System

This study aims to account for the underlying causes of spelling errors in hearing and deaf children who speak a dialectal form of Arabic that substantially differs from the standard written one. It presents a general overview of the spoken Arabic language and its written system, drawing attention to some of the phonological and orthographic regularities and irregularities used in constructing and decoding Arabic words and sentences. It also accounts for the diglossic factors that interfere with the process of phoneme-to-grapheme mapping. The spelling outcomes of a group of hearing children are compared with another group of orally educated deaf children, who in addition to the complexity and diglossity of Arabic, have limited hearing abilities. Both groups performed two written tasks, one representing the standard form and the other representing the dialect. These tasks identified the types of spelling and segmentation errors and the effects of the committed errors on children's awareness of the concept of word and word boundaries. Analysis of the results reveals their spelling errors' nature and frequencies, and progressively categorizes the most prominent errors in practicing each language form. The deaf group (n = 30) produced significantly more errors than the hearing group (n = 36) in the dysphonetic errors and the word omission categories. The findings indicate that the sociolinguistic context of the Arabic language and the orthographic nature of the Arabic script are both important factors affecting hearing and deaf children's awareness of the concept of word as well as their spelling performance. These results may enable educators to understand the underlying factors of Arabic spelling and produce targeted error correction strategies to maximize children's learning outcomes.

Phonological store and speechreading performance of Chinese students with hearing impairment

This study presents three experiments to examine the role of the phonological store component of working memory in the speechreading performance of students with hearing impairment (HI) in China. In Experiment 1, 86 high school students with HI completed an immediate serial recall task with four lists of monosyllabic words that differed in phonological and visual similarities. In Experiment 2 and Experiment 3, 40 participants divided into high or low phonological store capacity (PS) and 40 participants divided into high or low visual phonological story capacity (VPS) completed a speechreading test at the word, phrase and sentence levels. Results revealed that (1) immediate serial recall showed effects of phonological and visual similarity and their interaction; (2) there was no significant effect of phonological store capacities on speechreading; and (3) there was a significant effect of visual phonological store capacities on accuracy but not speed of speechreading. These findings point to a general phonological store system for visual orthographic coding and phonological coding that students with HI engage in speechreading in Chinese. It provides evidence for the contention that the visual-based coding has a more direct impact on speechreading performance of Chinese students with HI than the speech-based coding.

Phonology and orthography in deaf readers: Evidence from a lateralized ambiguity resolution paradigm

This study explored differences between the two hemispheres in processing written words among deaf readers. The main hypothesis was that impoverished phonological abilities of deaf readers may lead to atypical patterns of hemispheric involvement. To test this, deaf participants completed a metalinguistic awareness test to evaluate their orthographic and phonological awareness. Additionally, they were asked to read biased or neutral target sentences ending with an ambiguous homograph, with each sentence followed by the request to make a rapid lexical decision on a target word presented either to the left (LH) or right hemisphere (RH). Targets were either related to the more frequent, dominant, meaning of the homograph, to the less frequent, subordinate, meaning of the homograph or were not related at all. An Inverse Efficiency Score based on both response latency and accuracy was calculated and revealed that deaf readers' RH perform better than their LH. In contrast to hearing readers who in previous studies manifested left hemisphere dominance when completed the same research design. The apparent divergence of deaf readers' hemisphere lateralization from that of hearing counterparts seems to validate previous findings suggesting greater reliance on RH involvement among deaf individuals during visual word recognition.

Effect of age at cochlear implantation and at exposure to Cued Speech on literacy skills in deaf children

The aim of this study was to investigate how age at cochlear implantation (CI) and age at exposure to Cued Speech (CS, Manual system that resolves the ambiguity inherent lipreading) could impact literacy skills in deaf children. Ninety deaf children fitted with CI (early vs late) and exposed to CS (early vs late) from primary schools (from Grade 2 to Grade 5) took part in this study. Five literacy skills were assessed: phonological skills through phoneme deletion, reading (decoding and sentence comprehension), word spelling and vocabulary. The results showed that both age at CI and age at first exposure to CS had some influence on literacy skills but there was no interaction between these factors. This implies that the positive effects of age at CI, especially on all literacy skills in the younger children, were not strengthened by age at exposure to CS.

The N170 ERP component differs in laterality, distribution, and association with continuous reading measures for deaf and hearing readers

The temporo-occipitally distributed N170 ERP component is hypothesized to reflect print-tuning in skilled readers. This study investigated whether skilled deaf and hearing readers (matched on reading ability, but not phonological awareness) exhibit similar N170 patterns, given their distinct experiences learning to read. Thirty-two deaf and 32 hearing adults viewed words and symbol strings in a familiarity judgment task. In the N170 epoch (120-240ms) hearing readers produced greater negativity for words than symbols at left hemisphere (LH) temporo-parietal and occipital sites, while deaf readers only showed this asymmetry at occipital sites. Linear mixed effects regression was used to examine the influence of continuous measures of reading, spelling, and phonological skills on the N170 (120-240ms). For deaf readers, better reading ability was associated with a larger N170 over the right hemisphere (RH), but for hearing readers better reading ability was associated with a smaller RH N170. Better spelling ability was related to larger occipital N170s in deaf readers, but this relationship was weak in hearing readers. Better phonological awareness was associated with smaller N170s in the LH for hearing readers, but this association was weaker and in the RH for deaf readers. The results support the phonological mapping hypothesis for a left-lateralized temporo-parietal N170 in hearing readers and indicate that skilled reading is characterized by distinct patterns of neural tuning to print in deaf and hearing adults.

Early use of phonological codes in deaf readers: An ERP study

Previous studies suggest that deaf readers use phonological information of words when it is explicitly demanded by the task itself. However, whether phonological encoding is automatic remains controversial. The present experiment examined whether adult congenitally deaf readers show evidence of automatic use of phonological information during visual word recognition. In an ERP masked priming lexical decision experiment, deaf participants responded to target words preceded by a pseudohomophone (koral - CORAL) or an orthographic control prime (toral - CORAL). Responses were faster for the pseudohomophone than for the orthographic control condition. The N250 and N400 amplitudes were reduced for the pseudohomophone when compared to the orthographic control condition. Furthermore, the magnitude of both the behavioral and the ERP pseudohomophone effects in deaf readers was similar to that of a group of well-matched hearing controls. These findings reveal that phonological encoding is available to deaf readers from the early stages of visual word recognition. Finally, the pattern of correlations of phonological priming with reading ability suggested that the amount of sub-lexical use of phonological information could be a main contributor to reading ability for hearing but not for deaf readers.

The Neural Basis of Speech Perception through Lipreading and Manual Cues: Evidence from Deaf Native Users of Cued Speech

We present here the first neuroimaging data for perception of Cued Speech (CS) by deaf adults who are native users of CS. CS is a visual mode of communicating a spoken language through a set of manual cues which accompany lipreading and disambiguate it. With CS, sublexical units of the oral language are conveyed clearly and completely through the visual modality without requiring hearing. The comparison of neural processing of CS in deaf individuals with processing of audiovisual (AV) speech in normally hearing individuals represents a unique opportunity to explore the similarities and differences in neural processing of an oral language delivered in a visuo-manual vs. an AV modality. The study included deaf adult participants who were early CS users and native hearing users of French who process speech audiovisually. Words were presented in an event-related fMRI design. Three conditions were presented to each group of participants. The deaf participants saw CS words (manual + lipread), words presented as manual cues alone, and words presented to be lipread without manual cues. The hearing group saw AV spoken words, audio-alone and lipread-alone. Three findings are highlighted. First, the middle and superior temporal gyrus (excluding Heschl's gyrus) and left inferior frontal gyrus pars triangularis constituted a common, amodal neural basis for AV and CS perception. Second, integration was inferred in posterior parts of superior temporal sulcus for audio and lipread information in AV speech, but in the occipito-temporal junction, including MT/V5, for the manual cues and lipreading in CS. Third, the perception of manual cues showed a much greater overlap with the regions activated by CS (manual + lipreading) than lipreading alone did. This supports the notion that manual cues play a larger role than lipreading for CS processing. The present study contributes to a better understanding of the role of manual cues as support of visual speech perception in the framework of the multimodal nature of human communication.

Working memory, short-term memory and reading proficiency in school-age children with cochlear implants

OBJECTIVE

The objective of the study was to examine short-term memory and working memory through both visual and auditory tasks in school-age children with cochlear implants. The relationship between the performance on these cognitive skills and reading as well as language outcomes were examined in these children.

METHODS

Ten children between the ages of 7 and 11 years with early-onset bilateral severe-profound hearing loss participated in the study. Auditory and visual short-term memory, auditory and visual working memory subtests and verbal knowledge measures were assessed using the Woodcock Johnson III Tests of Cognitive Abilities, the Wechsler Intelligence Scale for Children-IV Integrated and the Kaufman Assessment Battery for Children II. Reading outcomes were assessed using the Woodcock Reading Mastery Test III.

RESULTS

Performance on visual short-term memory and visual working memory measures in children with cochlear implants was within the average range when compared to the normative mean. However, auditory short-term memory and auditory working memory measures were below average when compared to the normative mean. Performance was also below average on all verbal knowledge measures. Regarding reading outcomes, children with cochlear implants scored below average for listening and passage comprehension tasks and these measures were positively correlated to visual short-term memory, visual working memory and auditory short-term memory. Performance on auditory working memory subtests was not related to reading or language outcomes.

CONCLUSIONS

The children with cochlear implants in this study demonstrated better performance in visual (spatial) working memory and short-term memory skills than in auditory working memory and auditory short-term memory skills. Significant positive relationships were found between visual working memory and reading outcomes. The results of the study provide support for the idea that WM capacity is modality specific in children with hearing loss. Based on these findings, reading instruction that capitalizes on the strengths in visual short-term memory and working memory is suggested for young children with early-onset hearing loss.

Phonological Awareness at 5 years of age in Children who use Hearing Aids or Cochlear Implants

Children with hearing loss typically underachieve in reading, possibly as a result of their underdeveloped phonological skills. This study addressed the questions of whether the development of phonological awareness (PA) is influenced by 1) the degree of hearing loss; and 2) whether performance of children with severe-profound hearing loss differed according to the hearing devices used. Drawing on data collected as part of the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI, www.

OUTCOMES

nal.gov.au) study, the authors found that sound-matching scores of children with hearing loss ranging from mild to profound degrees were, on average, within the normal range. The degree of hearing loss did not have a significant impact on scores, but there was a non-significant tendency for the proportion of children who achieved zero scores to increase with increase in hearing loss. For children with severe hearing loss, there was no significant group difference in scores among children who used bilateral hearing aids, bimodal fitting (a cochlear implant and a hearing aid in contralateral ears), and bilateral cochlear implants. Although there is a need for further prospective research, professionals have an important role in targeting PA skills for rehabilitation of young children with hearing loss.

The deaf utilize phonological representations in visually presented verbal memory tasks

The phonological abilities of congenitally deaf individuals are inferior to those of people who can hear. However, deaf individuals can acquire spoken languages by utilizing orthography and lip-reading. The present study used functional magnetic resonance imaging (fMRI) to show that deaf individuals utilize phonological representations via a mnemonic process. We compared the brain activation of deaf and hearing participants while they memorized serially visually presented Japanese kana letters (Kana), finger alphabets (Finger), and Arabic letters (Arabic). Hearing participants did not know which finger alphabets corresponded to which language sounds, whereas deaf participants did. All of the participants understood the correspondence between Kana and their language sounds. None of the participants knew the correspondence between Arabic and their language sounds, so this condition was used as a baseline. We found that the left superior temporal gyrus (STG) was activated by phonological representations in the deaf group when memorizing both Kana and Finger. Additionally, the brain areas associated with phonological representations for Finger in the deaf group were the same as the areas for Kana in the hearing group. Overall, despite the fact that they are superior in visual information processing, deaf individuals utilize phonological rather than visual representations in visually presented verbal memory.

Analysis of reading strategies in deaf adults as a function of their language and meta-phonological skills

The first aim of this study was to examine the mechanisms used in reading sentences by deaf adults who had completed secondary or higher education. Previous data allowed us to hypothesize that they used the key word strategy, consisting of identifying (some of) the frequent content words, and deriving an overall representation of the sentence's meaning ignoring the function words. The results supported the hypothesis. The second aim was to establish the relationships between this strategy and the linguistic and phonological abilities of deaf participants. The results show that vocabulary increased with reading level, but syntax, evaluated with the use of function words, did not. This suggests that using the key word strategy during long periods of time increases knowledge of content words but not syntax, probably because function words are neglected by this strategy. The results also showed that the deaf participants had a fairly large orthographical lexicon. This implies that the extensive use of the key word strategy allows them to store lexical information. The next question was whether the written word representations of the deaf participants were memorized as mere logograms, or if they had been stored in connection with the phonological representations of the corresponding words. The metaphonological tasks conducted produced evidence indicating that deaf participants used both orthographic and phonological representations. A factor analysis of the metaphonological tasks together with reading and spelling confirmed that both factors were necessary to explain the whole variance in the deaf group.

How is the McGurk effect modulated by Cued Speech in deaf and hearing adults?

Speech perception for both hearing and deaf people involves an integrative process between auditory and lip-reading information. In order to disambiguate information from lips, manual cues from Cued Speech may be added. Cued Speech (CS) is a system of manual aids developed to help deaf people to clearly and completely understand speech visually (Cornett, 1967). Within this system, both labial and manual information, as lone input sources, remain ambiguous. Perceivers, therefore, have to combine both types of information in order to get one coherent percept. In this study, we examined how audio-visual (AV) integration is affected by the presence of manual cues and on which form of information (auditory, labial or manual) the CS receptors primarily rely. To address this issue, we designed a unique experiment that implemented the use of AV McGurk stimuli (audio /pa/ and lip-reading /ka/) which were produced with or without manual cues. The manual cue was congruent with either auditory information, lip information or the expected fusion. Participants were asked to repeat the perceived syllable aloud. Their responses were then classified into four categories: audio (when the response was /pa/), lip-reading (when the response was /ka/), fusion (when the response was /ta/) and other (when the response was something other than /pa/, /ka/ or /ta/). Data were collected from hearing impaired individuals who were experts in CS (all of which had either cochlear implants or binaural hearing aids; N = 8), hearing-individuals who were experts in CS (N = 14) and hearing-individuals who were completely naïve of CS (N = 15). Results confirmed that, like hearing-people, deaf people can merge auditory and lip-reading information into a single unified percept. Without manual cues, McGurk stimuli induced the same percentage of fusion responses in both groups. Results also suggest that manual cues can modify the AV integration and that their impact differs between hearing and deaf people.

The neurobiology of rhyme judgment by deaf and hearing adults: an ERP study

We used electrophysiology to determine the time course and distribution of neural activation during an English word rhyme task in hearing and congenitally deaf adults. Behavioral performance by hearing participants was at ceiling and their ERP data replicated two robust effects repeatedly observed in the literature. First, a sustained negativity, termed the contingent negative variation, was elicited following the first stimulus word. This negativity was asymmetric, being more negative over the left than right sites. The second effect we replicated in hearing participants was an enhanced negativity (N450) to nonrhyming second stimulus words. This was largest over medial, parietal regions of the right hemisphere. Accuracy on the rhyme task by the deaf group as a whole was above chance level, yet significantly poorer than hearing participants. We examined only ERP data from deaf participants who performed the task above chance level (n = 9). We observed indications of subtle differences in ERP responses between deaf and hearing groups. However, overall the patterns in the deaf group were very similar to that in the hearing group. Deaf participants, just as hearing participants, showed greater negativity to nonrhyming than rhyming words. Furthermore the onset latency of this effect was the same as that observed in hearing participants. Overall, the neural processes supporting explicit phonological judgments are very similar in deaf and hearing people, despite differences in the modality of spoken language experience. This supports the suggestion that phonological processing is to a large degree amodal or supramodal.

The development of word recognition, sentence comprehension, word spelling, and vocabulary in children with deafness: a longitudinal study

BACKGROUND

Only a small number of longitudinal studies have been conducted to assess the literacy skills of children with hearing impairment. The results of these studies are inconsistent with regard to the importance of phonology in reading acquisition as is the case in studies with hearing children. Colin, Magnan, Ecalle, and Leybaert (2007) revealed the important role of early phonological skills and the contribution of the factor of age of exposure to Cued Speech (CS: a manual system intended to resolve the ambiguities inherent to speechreading) to subsequent reading acquisition (from kindergarten to first grade) in children with deafness. The aim of the present paper is twofold: (1) to confirm the role of early exposure to CS in the development of the linguistic skills necessary in order to learn reading and writing in second grade; (2) to reveal the possible existence of common factors other than CS that may influence literacy performances and explain the inter-individual difference within groups of children with hearing impairment.

METHOD

Eighteen 6-year-old hearing-impaired and 18 hearing children of the same chronological age were tested from kindergarten to second grade. The children with deafness had either been exposed to CS at an early age, at home and before kindergarten (early-CS group), or had first been exposed to it when they entered kindergarten (late-CS group) or first grade (beginner-CS group). Children were given implicit and explicit phonological tasks, silent reading tasks (word recognition and sentence comprehension), word spelling, and vocabulary tasks.

RESULTS

Children in the early-CS group outperformed those of the late-CS and beginner-CS groups in phonological tasks from first grade to second grade. They became better readers and better spellers than those from the late-CS group and the beginner-CS group. Their performances did not differ from those of hearing children in any of the tasks except for the receptive vocabulary test. Thus early exposure to CS seems to permit the development of linguistic skills necessary in order to learn reading and writing. The possible contribution of other factors to the acquisition of literacy skills by children with hearing impairment will be discussed.

Lexical processing in deaf readers: an FMRI investigation of reading proficiency

Individuals with significant hearing loss often fail to attain competency in reading orthographic scripts which encode the sound properties of spoken language. Nevertheless, some profoundly deaf individuals do learn to read at age-appropriate levels. The question of what differentiates proficient deaf readers from less-proficient readers is poorly understood but topical, as efforts to develop appropriate and effective interventions are needed. This study uses functional magnetic resonance imaging (fMRI) to examine brain activation in deaf readers (N = 21), comparing proficient (N = 11) and less proficient (N = 10) readers’ performance in a widely used test of implicit reading. Proficient deaf readers activated left inferior frontal gyrus and left middle and superior temporal gyrus in a pattern that is consistent with regions reported in hearing readers. In contrast, the less-proficient readers exhibited a pattern of response characterized by inferior and middle frontal lobe activation (right>left) which bears some similarity to areas reported in studies of logographic reading, raising the possibility that these individuals are using a qualitatively different mode of orthographic processing than is traditionally observed in hearing individuals reading sound-based scripts. The evaluation of proficient and less-proficient readers points to different modes of processing printed English words. Importantly, these preliminary findings allow us to begin to establish the impact of linguistic and educational factors on the neural systems that underlie reading achievement in profoundly deaf individuals.

Factors distinguishing skilled and less skilled deaf readers: evidence from four orthographies

This study aims to enhance understanding of the factors underlying variance in the reading comprehension skills of prelingually deaf individuals. Participants were 213 sixth through tenth graders with prelingual deafness recruited from four orthographic backgrounds (Hebrew, Arabic, English, and German) and allocated to three distinct reading profiles (levels). A sentence comprehension test manipulating the semantic plausibility of sentences and a word processing experiment requiring rapid determination of the semantic relationship between two real words or between a real word and a pseudohomophonic letter string were used to determine the factors distinguishing skilled from less skilled deaf readers. Findings point to deficits in structural (syntactic) knowledge and deficient knowledge structures, rather than differences in phonological processing skills, as making that distinction. Moreover, the acquisition of such knowledge seems to be modified by particularities of the read orthography.

Reading achievement in relation to phonological coding and awareness in deaf readers: a meta-analysis

The relation between reading ability and phonological coding and awareness (PCA) skills in individuals who are severely and profoundly deaf was investigated with a meta-analysis. From an initial set of 230 relevant publications, 57 studies were analyzed that experimentally tested PCA skills in 2,078 deaf participants. Half of the studies found statistically significant evidence for PCA skills and half did not. A subset of 25 studies also tested reading proficiency and showed a wide range of effect sizes. Overall PCA skills predicted 11% of the variance in reading proficiency in the deaf participants. Other possible modulating factors, such as task type and reading grade level, did not explain the remaining variance. In 7 studies where it was measured, language ability predicted 35% of the variance in reading proficiency. These meta-analytic results indicate that PCA skills are a low to moderate predictor of reading achievement in deaf individuals and that other factors, most notably language ability, have a greater influence on reading development, as has been found to be the case in the hearing population.

Phonological awareness, vocabulary, and reading in deaf children with cochlear implants

PURPOSE

To explore the phonological awareness skills of deaf children with cochlear implants (CIs) and relationships with vocabulary and reading development.

METHOD

Forty-three deaf children with implants who were between 5 and 15 years of age were tested; 21 had been implanted at around 2.5 years of age (Early CI group), and 22 had been implanted at around 5 years of age (Late CI group). Two control groups-a deaf hearing aided group (16 children) and a typically developing group of hearing children (19 children)-were also tested. All children received a battery of phonological processing tasks along with measures of reading, vocabulary, and speechreading. Analyses focus on deaf children within the normal IQ range (n = 53).

RESULTS

Age at cochlear implantation had a significant effect on vocabulary and reading outcomes when quotient scores were calculated. Individual differences in age at implant, duration of fit, phonological development, vocabulary development, auditory memory, visual memory, and speech intelligibility were all strongly associated with progress in reading for the deaf implanted children. Patterns differed somewhat depending on whether quotient scores or standard scores were used.

CONCLUSIONS

Cochlear implantation is associated with development of the oral language, auditory memory, and phonological awareness skills necessary for developing efficient word recognition skills. There is a benefit of earlier implantation.

Reading mechanisms in orally educated deaf adults

This study was aimed at determining the reading mechanisms used by deaf adults who had completed secondary or higher education. Our main hypothesis was that they used a reading strategy consisting of identifying (some of) the key words of sentences and deriving an overall representation of their meaning. All the predictions derived from this hypothesis were supported by the results. In addition, an orthographic test showed that they possessed an orthographic lexicon richer than hearing group of the same reading level. This is in harmony with the key word strategy. Finally, most of the deaf participants (12 out of 14) reached scores in metaphonological tasks slightly under the level reached by the hearing group. It is speculated that the mechanisms of reading and spelling at play in deaf adults are based on phonological representations of words.

Is there an alternative cerebral network associated with enhanced phonological processing in deaf speech-users? An exceptional case

Most people born deaf and exposed to oral language show scant evidence of sensitivity to the phonology of speech when processing written language. In this respect they differ from hearing people. However, occasionally, a prelingually deaf person can achieve good processing of written language in terms of phonological sensitivity and awareness, and in this respect appears exceptional. We report the pattern of event-related fMRI activation in such a deaf reader while performing a rhyme-judgment on written words with similar spelling endings that do not provide rhyme clues. The left inferior frontal gyrus pars opercularis and the left inferior parietal lobe showed greater activation for this task than for a letter-string identity matching task. This participant was special in this regard, showing significantly greater activation in these regions than a group of hearing participants with a similar level of phonological and reading skill. In addition, SR showed activation in the left mid-fusiform gyrus; a region which did not show task-specific activation in the other respondents. The pattern of activation in this exceptional deaf reader was also unique compared with three deaf readers who showed limited phonological processing. We discuss the possibility that this pattern of activation may be critical in relation to phonological decoding of the written word in good deaf readers whose phonological reading skills are indistinguishable from those of hearing readers.

Phonological awareness and short-term memory in hearing and deaf individuals of different communication backgrounds

Previous work in deaf populations on phonological coding and working memory, two skills thought to play an important role in the acquisition of written language skills, have focused primarily on signers or did not clearly identify the subjects' native language and communication mode. In the present study, we examined the effect of sensory experience, early language experience, and communication mode on the phonological awareness skills and serial recall of linguistic items in deaf and hearing individuals of different communicative and linguistic backgrounds: hearing nonsigning controls, hearing users of ASL, deaf users of ASL, deaf oral users of English, and deaf users of cued speech. Since many current measures of phonological awareness skills are inappropriate for deaf populations on account of the verbal demands in the stimuli or response, we devised a nonverbal phonological measure that addresses this limitation. The Phoneme Detection Test revealed that deaf cuers and oral users, but not deaf signers, performed as well as their hearing peers when detecting phonemes not transparent in the orthography. The second focus of the study examined short-term memory skills and found that in response to the traditional digit span as well as an experimental visual version, digit-span performance was similar across the three deaf groups, yet deaf subjects' retrieval was lower than that of hearing subjects. Our results support the claim (Bavelier et al., 2006) that lexical items processed in the visual-spatial modality are not as well retained as information processed in the auditory channel. Together these findings show that the relationship between working memory, phonological coding, and reading may not be as tightly interwoven in deaf students as would have been predicted from work conducted in hearing students.

The nature and efficiency of the word reading strategies of orally raised deaf students

The main objective of this study was to unveil similarities and differences in the word reading strategies of orally raised individuals with prelingual deafness and hearing individuals. Relevant data were gathered by a computerized research paradigm asking participants to make rapid same/different judgments for words. There were three distinct study conditions: (a) a visual condition manipulating the visual-perceptional properties of the target word pairs, (b) a phonological condition manipulating their phonological properties, and (c) a control condition. Participants were 31 high school and postgraduate students with prelingual deafness and 59 hearing students (the control group). Analysis of response latencies and accuracy in the three study conditions suggests that the word reading strategies the groups relied upon to process the stimulus materials were of the same nature. Evidence further suggests that prelingual deafness does not undermine the efficiency with which readers use these strategies. To gain a broader understanding of the obtained evidence, participants' performance in the word processing experiment was correlated with their phonemic awareness-the hypothesized hallmark of proficient word reading-and their reading comprehension skills. Findings are discussed with reference to a reading theory that assigns phonology a central role in proficient word reading.

Phonological awareness and decoding in deaf/hard-of-hearing students who use visual phonics

Visual phonics, a system of 45 hand and symbol cues that represent the phonemes of spoken English, has been used as a tool in literacy instruction with deaf/hard-of-hearing (DHH) students for over 20 years. Despite years of anecdotal support, there is relatively little published evidence of its impact on reading achievement. This study was designed to examine the relationship between performance on a phonological awareness task, performance on a decoding task, reading ability, and length of time in literacy instruction with visual phonics for 10 DHH kindergarten through Grade 3 students receiving academic instruction with sign-supported English and American Sign Language. Findings indicate that these students were able to use phonological information to make rhyme judgments and to decode; however, no relationship between performance on reading ability and length of time in literacy instruction with visual phonics was found.

Phonological processing in relation to reading: An fMRI study in deaf readers

Without special education, early deprivation of auditory speech input, hinders the development of phonological representations and may alter the neural mechanisms of reading. By using fMRI during lexical and rhyming decision tasks, we compared in hearing and pre-lingually deaf subjects the neural activity in functional regions of interest (ROIs) engaged in reading. The results show in deaf readers significantly higher activation in the ROIs relevant to the grapho-phonological route, but also in the posterior medial frontal cortex (pMFC) and the right inferior frontal gyrus (IFG). These adjustments may be interpreted within the dual route model of reading as an alternative strategy, which gives priority to rule-based letter-to-sound conversion. Activation in the right IFG would account for compensation mechanisms based on phonological recoding and inner speech while activation in the posterior medial frontal cortex (pMFC) may relate to the cognitive effort called for by the alternative strategy. Our data suggest that the neural mechanisms of reading are shaped by the auditory experience of speech.

Phonological awareness in deaf children who use cochlear implants

A short-term longitudinal study was conducted to investigate possible benefits of cochlear implant (CI) use on the development of phonological awareness in deaf children. Nineteen CI users were tested on 2 occasions. Two groups of deaf children using hearing aids were tested once: 11 profoundly deaf and 10 severely deaf children. A battery of tests was designed to investigate syllable, rhyme, and phoneme awareness. Syllable awareness in the CI users was equivalent to that of the severely deaf group, and rhyme and phoneme awareness was similar to that of the profoundly deaf children using hearing aids. CI use affords some benefit to the development of phonological awareness. The results from this study indicate that this enhancement is first observable at the syllable level.

Neurolinguistic development in deaf children: the effect of early language experience

Recent investigations have indicated a relationship between the development of cerebral lateralization for processing language and the level of development of linguistic skills in hearing children. The research on cerebral lateralization for language processing in deaf persons is compatible with this view. We have argued that the absence of appropriate input during a critical time window creates a risk for deaf children that the initial bias for left-hemisphere specialization will be distorted or disappear. Two experiments were conducted to test this hypothesis The results of these investigations showed that children educated early and intensively with cued speech or with sign language display more evidence of left-hemisphere specialization for the processing of their native language than do those who have been exposed later and less intensively to those languages.

Phonological similarity effects in memory for serial order of cued speech

Experiment I investigated memory for serial order by congenitally, profoundly deaf individuals, 6-22 years old, for words presented via Cued Speech (CS) without sound. CS is a system that resolves the ambiguity inherent in speechreading through the addition of manual cues. The phonological components of CS are mouth shape, hand shape, and hand placement. Of interest was whether the recall of serial order was lower for lists of words similar in both mouth shape and hand placement, or similar in mouth shape only, or in hand placement only than for control lists designed to minimize these similarities. Deaf participants showed lower performance on the three similar lists than the control lists, suggesting that deaf individuals use the phonology of CS to support their recall. In Experiment II, the same lists were administered to two groups of hearing participants. One group, experienced producers of CS, received the CS stimuli without sound; the other group, unfamiliar with CS, received the CS stimuli audiovisually. Participants experienced with CS showed no effect of hand placement similarity, suggesting that this effect may be related to the linguistic experience of deaf participants. The recency effect was greater in the hearing group provided with sound, indicating that the traces left by auditory stimuli are perceptually more salient than those left by the visual stimuli encountered in CS.

Phonology acquired through the eyes and spelling in deaf children

Hearing and deaf children, ranging in age from 6 years 8 months to 14 years 4 months, and matched for general spelling level, were required to spell high-frequency and low-frequency words. Of interest was performance in relation to degree of exposure to Cued Speech (CS), which is a system delivering phonetically augmented speechreading through the visual modality. Groups were (a) hearing children, (b) deaf children exposed early and intensively to CS at home (CS-Home), and (c) deaf children exposed to CS later and at school only (CS-School). Most of the spelling productions of hearing children as well as of CS-Home children were phonologically accurate for high-frequency as well as for low-frequency words. CS-School children, who had less specified phonological representations, made a lower proportion of phonologically accurate spellings. These findings indicate that the accuracy of phonological representations, independent of the modality (acoustic versus visual) through which spoken language is perceived, determines the acquisition of phonology-to-orthography mappings. Analyses of the spelling productions indicate that the acquisition of orthographic representations of high precision depends on fully specified phonological representations.