Language deficits in dyslexic children: speech perception, phonology, and morphology

Functional benefits of continuous vs. categorical listening strategies on the neural encoding and perception of noise-degraded speech

Acoustic information in speech changes continuously, yet listeners form discrete perceptual categories to ease the demands of perception. Being a more continuous/gradient as opposed to a more discrete/categorical listener may be further advantageous for understanding speech in noise by increasing perceptual flexibility and resolving ambiguity. The degree to which a listener's responses to a continuum of speech sounds are categorical versus continuous can be quantified using visual analog scaling (VAS) during speech labeling tasks. Here, we recorded event-related brain potentials (ERPs) to vowels along an acoustic-phonetic continuum (/u/ to /a/) while listeners categorized phonemes in both clean and noise conditions. Behavior was assessed using standard two alternative forced choice (2AFC) and VAS paradigms to evaluate categorization under task structures that promote discrete vs. continuous hearing, respectively. Behaviorally, identification curves were steeper under 2AFC vs. VAS categorization but were relatively immune to noise, suggesting robust access to abstract, phonetic categories even under signal degradation. Behavioral slopes were correlated with listeners' QuickSIN scores; shallower slopes corresponded with better speech in noise performance, suggesting a perceptual advantage to noise degraded speech comprehension conferred by a more gradient listening strategy. At the neural level, P2 amplitudes and latencies of the ERPs were modulated by task and noise; VAS responses were larger and showed greater noise-related latency delays than 2AFC responses. More gradient responders had smaller shifts in ERP latency with noise, suggesting their neural encoding of speech was more resilient to noise degradation. Interestingly, source-resolved ERPs showed that more gradient listening was also correlated with stronger neural responses in left superior temporal gyrus. Our results demonstrate that listening strategy modulates the categorical organization of speech and behavioral success, with more continuous/gradient listening being advantageous to sentential speech in noise perception.

Individual differences in the consistency of neural and behavioural responses to speech sounds

There are documented individual differences among adults in the consistency of speech sound processing, both at neural and behavioural levels. Some adults show more consistent neural responses to speech sounds than others, as measured by an event-related potential called the frequency-following response (FFR); similarly, some adults show more consistent behavioural responses to native speech sounds than others, as measured by two-alternative forced choice (2AFC) and visual analog scaling (VAS) tasks. Adults also differ in how successfully they can perceive non-native speech sounds. Interestingly, it remains unclear whether these differences are related within individuals. In the current study, native English-speaking adults completed native phonetic perception tasks (2AFC and VAS), a non-native (German) phonetic perception task, and an FFR recording session. From these tasks, we derived measures of the consistency of participants' neural and behavioural responses to native speech as well as their non-native perception ability. We then examined the relationships among individual differences in these measures. Analysis of the behavioural measures revealed that more consistent responses to native sounds predicted more successful perception of unfamiliar German sounds. Analysis of neural and behavioural data did not reveal clear relationships between FFR consistency and our phonetic perception measures. This multimodal work furthers our understanding of individual differences in speech processing among adults, and may eventually lead to individualized approaches for enhancing non-native language acquisition in adulthood.

Functional benefits of continuous vs. categorical listening strategies on the neural encoding and perception of noise-degraded speech

Acoustic information in speech changes continuously, yet listeners form discrete perceptual categories to ease the demands of perception. Being a more continuous/gradient as opposed to a discrete/categorical listener may be further advantageous for understanding speech in noise by increasing perceptual flexibility and resolving ambiguity. The degree to which a listener's responses to a continuum of speech sounds are categorical versus continuous can be quantified using visual analog scaling (VAS) during speech labeling tasks. Here, we recorded event-related brain potentials (ERPs) to vowels along an acoustic-phonetic continuum (/u/ to /a/) while listeners categorized phonemes in both clean and noise conditions. Behavior was assessed using standard two alternative forced choice (2AFC) and VAS paradigms to evaluate categorization under task structures that promote discrete (2AFC) vs. continuous (VAS) hearing, respectively. Behaviorally, identification curves were steeper under 2AFC vs. VAS categorization but were relatively immune to noise, suggesting robust access to abstract, phonetic categories even under signal degradation. Behavioral slopes were positively correlated with listeners' QuickSIN scores, suggesting a behavioral advantage for speech in noise comprehension conferred by gradient listening strategy. At the neural level, electrode level data revealed P2 peak amplitudes of the ERPs were modulated by task and noise; responses were larger under VAS vs. 2AFC categorization and showed larger noise-related delay in latency in the VAS vs. 2AFC condition. More gradient responders also had smaller shifts in ERP latency with noise, suggesting their neural encoding of speech was more resilient to noise degradation. Interestingly, source-resolved ERPs showed that more gradient listening was also correlated with stronger neural responses in left superior temporal gyrus. Our results demonstrate that listening strategy (i.e., being a discrete vs. continuous listener) modulates the categorical organization of speech and behavioral success, with continuous/gradient listening being more advantageous to speech in noise perception.

Hearing in categories aids speech streaming at the "cocktail party"

Our perceptual system bins elements of the speech signal into categories to make speech perception manageable. Here, we aimed to test whether hearing speech in categories (as opposed to a continuous/gradient fashion) affords yet another benefit to speech recognition: parsing noisy speech at the "cocktail party." We measured speech recognition in a simulated 3D cocktail party environment. We manipulated task difficulty by varying the number of additional maskers presented at other spatial locations in the horizontal soundfield (1-4 talkers) and via forward vs. time-reversed maskers, promoting more and less informational masking (IM), respectively. In separate tasks, we measured isolated phoneme categorization using two-alternative forced choice (2AFC) and visual analog scaling (VAS) tasks designed to promote more/less categorical hearing and thus test putative links between categorization and real-world speech-in-noise skills. We first show that listeners can only monitor up to ~3 talkers despite up to 5 in the soundscape and streaming is not related to extended high-frequency hearing thresholds (though QuickSIN scores are). We then confirm speech streaming accuracy and speed decline with additional competing talkers and amidst forward compared to reverse maskers with added IM. Dividing listeners into "discrete" vs. "continuous" categorizers based on their VAS labeling (i.e., whether responses were binary or continuous judgments), we then show the degree of IM experienced at the cocktail party is predicted by their degree of categoricity in phoneme labeling; more discrete listeners are less susceptible to IM than their gradient responding peers. Our results establish a link between speech categorization skills and cocktail party processing, with a categorical (rather than gradient) listening strategy benefiting degraded speech perception. These findings imply figure-ground deficits common in many disorders might arise through a surprisingly simple mechanism: a failure to properly bin sounds into categories.

Rules generalization in children with dyslexia

BACKGROUND

Rule learning (RL) is the ability to extract and generalize higher-order repetition-based structures. Children with Developmental Dyslexia (DD) often report difficulties in learning complex regularities in sequential stimuli, which might be due to the complexity of the rule to be learned. Learning high-order repetition-based rules represents a building block for the development of language skills.

AIMS

This study investigates the ability to extract and generalize simple, repetition-based visual rules (e.g., ABA) in 8-11-year-old children without (TD) and with a diagnosis of Development Dyslexia (DD) and its relationship with language and reading skills.

METHOD

Using a forced-choice paradigm, children were first exposed to a visual sequence containing a repetition-based rule (e.g., ABA) and were then asked to recognize familiar and novel rules generated by new visual elements. Standardized language and reading tests were also administered to both groups.

RESULTS

The accuracy in recognizing rules was above chance for both groups, even though DD children were less accurate than TD children, suggesting a less efficient RL mechanism in the DD group. Moreover, visual RL was positively correlated with both language and reading skills.

CONCLUSION

These results further confirm the crucial role of RL in the acquisition of linguistic skills and mastering reading abilities.

The ReadFree tool for the identification of poor readers: a validation study based on a machine learning approach in monolingual and minority-language children

In this study, we validated the "ReadFree tool", a computerised battery of 12 visual and auditory tasks developed to identify poor readers also in minority-language children (MLC). We tested the task-specific discriminant power on 142 Italian-monolingual participants (8-13 years old) divided into monolingual poor readers (N = 37) and good readers (N = 105) according to standardised Italian reading tests. The performances at the discriminant tasks of the "ReadFree tool" were entered into a classification and regression tree (CART) model to identify monolingual poor and good readers. The set of classification rules extracted from the CART model were applied to the MLC's performance and the ensuing classification was compared to the one based on standardised Italian reading tests. According to the CART model, auditory go-no/go (regular), RAN and Entrainment100bpm were the most discriminant tasks. When compared with the clinical classification, the CART model accuracy was 86% for the monolinguals and 76% for the MLC. Executive functions and timing skills turned out to have a relevant role in reading. Results of the CART model on MLC support the idea that ad hoc standardised tasks that go beyond reading are needed.

Reading and Math Achievement in Children With Dyslexia, Developmental Language Disorder, or Typical Development: Achievement Gaps Persist From Second Through Fourth Grades

We examined how children (N = 448) with separate or co-occurring developmental language disorder (DLD) and dyslexia performed on school-based measures of academic functioning between second and fourth grades. Children were recruited from 1 school district in the U.S. state of South Carolina via classroom screenings and met common research criteria for DLD and dyslexia. Growth curve models were used to examine the overall form of growth and differences between groups. Children with DLD and/or dyslexia in second grade showed early and persistent deficits on school-administered measures of reading and math. In second grade, children with typical development (TD) scored significantly higher than children with dyslexia-only and DLD-only, who did not differ from each other. Children with DLD+dyslexia scored significantly lower than all other groups. Only small differences in growth rates were observed, and gaps in second grade did not close. Despite lower academic performance, few children (20%-27%) with dyslexia and/or DLD had received specialized support services. Children with DLD-only received services at less than half the rate of dyslexia-only or DLD+dyslexia despite similar impacts on academic performance. Evidence of significant and persistent functional impacts in the context of low rates of support services in these children-especially those with DLD-only-highlights the need to raise awareness of these disorders.

Tracking reading skills and reading-related skills in dyslexia before (age 5) and after (ages 10-17) diagnosis

This study had three goals: to examine the stability of deficits in the phonological and lexical routes in dyslexia (group study), to determine the prevalence of dyslexia profiles (multiple-case study), and to identify the prediction of phonemic segmentation and discrimination skills before reading acquisition on future reading level. Among a group of 373 non-readers seen at age 5, 38 students were subsequently diagnosed as either consistent dyslexic readers (18 DYS) or consistent typical readers (20 TR). Their phonological and lexical reading skills were assessed at ages 10 and 17 and their phonemic segmentation and discrimination skills at age 5. In comparison with TR of the same chronological age (CA-TR), individuals with dyslexia demonstrated an impairment of the two reading routes, especially of the phonological reading route. In the comparison with younger TR (age 10) of the same reading level (RL-TR), only a deficit of the phonological route is observed. In the multiple-case study, the comparisons with CA-TR showed a prevalence of mixed profiles and very few dissociated profiles, whereas the comparison with RL-TR resulted mostly in two profiles depending on the measure: a phonological profile when accuracy was used and a delayed profile when speed was used. In addition, the correlations between early phonemic segmentation and discrimination skills (age 5) and later reading skills (age 17) were significant, and in the group of individuals with dyslexia, early phonemic segmentation skills significantly predicted these later reading skills. Phonological reading deficits are persistent and mainly caused by early phonemic impairments.

Individual Differences in Categorical Judgment of L2 Stops: A Link to Proficiency and Acoustic Cue-Weighting

This study investigated individual differences in Korean adult learners' categorical perception of L2 English stops with an aim to explore the relationship of gradient categorizations to perceptual sensitivity to acoustic cues and L2 proficiency. Korean young adult L2 learners of English (N = 49) participated in two speech perception tasks (visual analog scaling and forced-choice identification) in which they listened to English voiced and voiceless stops and Korean lax and aspirated stops with Voice Onset Time (VOT) and F0 manipulated to form a continuum. It was found that in both L1 and L2 stop perception, listeners' gradient category judgment was associated with greater reliance on language-specific redundant cues (i.e., F0 in L2 English and VOT in L1 Korean) and that in the perception of L2 stops, categorical listeners who tended to be less sensitive to F0 were the ones with a higher level of L2 English proficiency. The results suggest that the categorical manner of judging L2 stops reflects learners' better knowledge of L2-specific acoustic cue-weightings, based on which less relevant acoustic information is effectively suppressed.

Bioenvironmental Predictors of Childhood Reading and Speech Difficulties

PURPOSE

Reading and speech difficulties are common in childhood, yet it is not fully understood how much of their etiology is shared. This partly derives from methodological issues related to overlooking the potential co-occurrence between the two sets of difficulties. This study investigated the effects of five bioenvironmental predictors in a sample assessed for such co-occurrence.

METHOD

A combination of exploratory and confirmatory analyses was performed on longitudinal data from the National Child Development Study. Exploratory latent class analysis was performed on children's reading, speech, and language outcomes at ages 7 and 11 years. Membership in the obtained classes was modeled using a regression with sex and four early-life predictors: gestation period, socioeconomic status, maternal education, and the home reading environment.

RESULTS

The model yielded four latent classes that broadly reflected (1) average reading and speech, (2) excellent reading, (3) reading difficulties, and (4) speech difficulties. Early-life factors significantly predicted class membership. Male sex and preterm birth emerged as risk factors for both reading and speech difficulties. Protective effects against reading difficulties were identified for maternal education, and lower (but not higher) levels of socioeconomic status and the home reading environment.

CONCLUSIONS

Co-occurrence of reading and speech difficulties in the sample was low, and differential patterns of effect of the social environment were supported. Reading outcomes were under stronger malleable influence than speech outcomes.

Continuous dynamics in behavior reveal interactions between perceptual warping in categorization and speech-in-noise perception

Introduction

Spoken language comprehension requires listeners map continuous features of the speech signal to discrete category labels. Categories are however malleable to surrounding context and stimulus precedence; listeners' percept can dynamically shift depending on the sequencing of adjacent stimuli resulting in a warping of the heard phonetic category. Here, we investigated whether such perceptual warping-which amplify categorical hearing-might alter speech processing in noise-degraded listening scenarios.

Methods

We measured continuous dynamics in perception and category judgments of an acoustic-phonetic vowel gradient via mouse tracking. Tokens were presented in serial vs. random orders to induce more/less perceptual warping while listeners categorized continua in clean and noise conditions.

Results

Listeners' responses were faster and their mouse trajectories closer to the ultimate behavioral selection (marked visually on the screen) in serial vs. random order, suggesting increased perceptual attraction to category exemplars. Interestingly, order effects emerged earlier and persisted later in the trial time course when categorizing speech in noise.

Discussion

These data describe interactions between perceptual warping in categorization and speech-in-noise perception: warping strengthens the behavioral attraction to relevant speech categories, making listeners more decisive (though not necessarily more accurate) in their decisions of both clean and noise-degraded speech.

Altered engagement of the speech motor network is associated with reduced phonological working memory in autism

Nonword repetition, a common clinical measure of phonological working memory, involves component processes of speech perception, working memory, and speech production. Autistic children often show behavioral challenges in nonword repetition, as do many individuals with communication disorders. It is unknown which subprocesses of phonological working memory are vulnerable in autistic individuals, and whether the same brain processes underlie the transdiagnostic difficulty with nonword repetition. We used functional magnetic resonance imaging (fMRI) to investigate the brain bases for nonword repetition challenges in autism. We compared activation during nonword repetition in functional brain networks subserving speech perception, working memory, and speech production between neurotypical and autistic children. Autistic children performed worse than neurotypical children on nonword repetition and had reduced activation in response to increasing phonological working memory load in the supplementary motor area. Multivoxel pattern analysis within the speech production network classified shorter vs longer nonword-repetition trials less accurately for autistic than neurotypical children. These speech production motor-specific differences were not observed in a group of children with reading disability who had similarly reduced nonword repetition behavior. These findings suggest that atypical function in speech production brain regions may contribute to nonword repetition difficulties in autism.

Identifying the risk of dyslexia in bilingual children: The potential of language-dependent and language-independent tasks

This study investigates the linguistic processing and non-linguistic cognitive abilities of monolingual and bilingual children with and without reading difficulties and examines the relationship between these skills and reading. There were 72 Italian-speaking children: 18 monolingual good readers (MONO-GR, Mage = 10;4), 19 monolingual poor readers (MONO-PR, Mage = 10;3), 21 bilingual good readers (BI-GR, Mage = 10;6), and 16 bilingual poor readers (BI-PR, Mage = 10;6). All bilingual children spoke Italian as their L2. Children completed a battery of standardized Italian reading tests, language-dependent tasks: nonword repetition (NWR), sentence repetition (SR), and phonological awareness (PA), and language-independent tasks: timing anticipation, beat synchronization, inhibition control, auditory reaction time, and rapid automatized naming (RAN). Poor readers scored below good readers on the language-dependent tasks, including NWR, PA, and SR. Beat synchronization was the only language-independent task sensitive to reading ability, with poor readers showing greater variability than good readers in tapping to fast rhythms. SR was the only task influenced by language experience as bilinguals underperformed monolinguals on the task. Moreover, there were weak to moderate correlations between performance on some language-dependent tasks (NWR, PA), language-independent tasks (inhibition control, RAN), and reading measures. Performance on the experimental tasks (except for RAN) was not associated with the length of exposure to Italian. The results highlight the potential of NWR, PA, SR, and beat synchronization tasks in identifying the risk of dyslexia in bilingual populations. Future research is needed to validate these findings and to establish the tasks' diagnostic accuracy.

Morphological awareness in developmental dyslexia: Playing with nonwords in a morphologically rich language

Although phonological deficits are unanimously recognized as one of the key manifestations of developmental dyslexia, a growing body of research has reported impairments in morphological abilities. Our study aimed at casting further light on this domain by investigating the morphological awareness skills of 21 children with dyslexia (mean age 9.10 years old) and 24 children with typical development (mean age 10.3 years old). All children were monolingual speakers of Italian, which is a morphologically rich language characterized by complex inflectional and derivational paradigms. We developed an experimental protocol inspired by Berko’s Wug test and composed of 11 tasks addressing inflectional and derivational processes. Participants were asked to manipulate nonwords of various lexical categories, modeled after the phonotactic structure of Italian, and manipulation involved both word formation and base retrieval. Conditions of the experiments were based on verb conjugation classes differing in frequency, productivity, regularity, and formal transparency. Results confirmed that morphological skills are impaired in dyslexic children, who performed significantly more poorly than their age-matched peers in all tasks. Children with dyslexia were especially challenged by tasks and conditions requiring advanced morphological awareness skills, such as the retrieval of infinitives of infrequent and irregular conjugation classes. The educational and clinical implications of these findings are discussed.

Late mismatch negativity of lexical tone at age 8 predicts Chinese children’s reading ability at age 10

Background

Deficits in phonological processing are commonly reported in dyslexia but longitudinal evidence that poor speech perception compromises reading is scant. This 2-year longitudinal ERP study investigates changes in pre-attentive auditory processing that underlies categorical perception of mandarin lexical tones during the years children learn to read fluently. The main purpose of the present study was to explore the development of lexical tone categorical perception to see if it can predict children’s reading ability.

Methods

Both behavioral and electrophysiological measures were taken in this study. Auditory event-related potentials were collected with a passive listening oddball paradigm. Using a stimulus continuum spanning from one lexical tone category exemplar to another, we identified a between-category and a within-category tone deviant that were acoustically equidistant from a standard stimulus. The standard stimulus occurred on 80% of trials, and one of two deviants (between-category or within-category) equiprobably on the remaining trials. 8-year-old Mandarin speakers participated in both an initial ERP oddball paradigm and returned for a 2-year follow-up.

Results

The between-category MMN and within-category MMN significantly correlate with each other at age 8 (p = 0.001) but not at age 10. The between-category MMN at age 8 can predict children’s ability at age 10 (p = 0.03) but the within-category cannot.

Conclusion

The categorical perception of lexical tone is still developing from age 8 to age 10. The behavioral and electrophysiological results demonstrate that categorical perception of lexical tone at age 8 predicts children’s reading ability at age 10.

Categorical perception and influence of attention on neural consistency in response to speech sounds in adults with dyslexia

Developmental dyslexia is a common neurodevelopmental disorder that is associated with alterations in the behavioral and neural processing of speech sounds, but the scope and nature of that association is uncertain. It has been proposed that more variable auditory processing could underlie some of the core deficits in this disorder. In the current study, magnetoencephalography (MEG) data were acquired from adults with and without dyslexia while they passively listened to or actively categorized tokens from a /ba/-/da/ consonant continuum. We observed no significant group difference in active categorical perception of this continuum in either of our two behavioral assessments. During passive listening, adults with dyslexia exhibited neural responses that were as consistent as those of typically reading adults in six cortical regions associated with auditory perception, language, and reading. However, they exhibited significantly less consistency in the left supramarginal gyrus, where greater inconsistency correlated significantly with worse decoding skills in the group with dyslexia. The group difference in the left supramarginal gyrus was evident only when neural data were binned with a high temporal resolution and was only significant during the passive condition. Interestingly, consistency significantly improved in both groups during active categorization versus passive listening. These findings suggest that adults with dyslexia exhibit typical levels of neural consistency in response to speech sounds with the exception of the left supramarginal gyrus and that this consistency increases during active versus passive perception of speech sounds similarly in the two groups.

The lexical status of verbs among typical and dyslexic native Arabic readers: a developmental model

The goal of this study was to investigate the development of mental lexicon organization among typical and dyslexic native Arabic readers. The participants included 271 students, divided into dyslexic readers, age-matched typical readers, and typical readers 2 years younger. The lexical status of root and pattern morphemes was examined using two priming paradigms: masked priming and the cross-modal immediate repetition task. We conducted two visual lexical decision tasks (Experiment 1 for verb pattern, Experiment 3 for verb roots), and two auditory decision tasks (Experiment 2 for verb pattern, Experiment 4 for verb roots). In the visual tasks, the participants were asked to decide whether a visual stimulus was a real word or not by pressing the laptop keyboard's "yes" or "no" button. The auditory experiments were conducted similarly to the visual experiments, except that the stimuli were auditory, to clarify the locus of the morphological deficit observed in the visual test of the dyslexic students, should there be such failures. Analysis of Experiment 1 showed that verb patterns are not lexical entities with a role in organizing the mental lexicon among typical and dyslexic readers of different ages. However, Experiment 3 indicated that roots do indeed constitute lexical entities with a role in organizing the mental lexicon among normal and dyslexic readers of different ages. In Experiment 2, the auditory-morpho priming effect in the word pattern test was stronger among dyslexic and young readers than among more skilled readers, and contributed to speeding up lexical decisions more than its quality, among all research groups. In Experiment 4, the auditory-morpho priming effect in the root test was stronger than the visual effect among all participants, and contributed to hastening lexical decisions and improving the quality of the answers (success percentage). The results showed that roots contribute to the reading process. However, their contribution is different among dyslexic readers. Its construction is slower and different from that of typical readers, whereas word patterns have no lexical representation among the three reader groups that are likely to facilitate lexical decisions. The results are discussed with reference to the latest research literature on morpheme type (root or pattern).

Later but Not Weaker: Neural Categorization of Native Vowels of Children at Familial Risk of Dyslexia

Although allophonic speech processing has been hypothesized to be a contributing factor in developmental dyslexia, experimental evidence is limited and inconsistent. The current study compared the categorization of native similar sounding vowels of typically developing (TD) children and children at familial risk (FR) of dyslexia. EEG response was collected in a non-attentive passive oddball paradigm from 35 TD and 35 FR Dutch 20-month-old infants who were matched on vocabulary. The children were presented with two nonwords “giep” [ɣip] and “gip” [ɣIp] that contrasted solely with respect to the vowel. In the multiple-speaker condition, both nonwords were produced by twelve different speakers while in the single-speaker condition, single tokens of each word were used as stimuli. For both conditions and for both groups, infant positive mismatch response (p-MMR) was elicited, and the p-MMR amplitude was comparable between the two groups, although the FR children had a later p-MMR peak than the TD children in the multiple-speaker condition. These findings indicate that FR children are able to categorize speech sounds, but that they may do so in a more effortful way than TDs.

Benefit of Bilateral Cochlear Implantation on Phonological Processing Skills in Deaf Children

HYPOTHESIS

Children with bilateral cochlear implants (CIs) would have better phonological processing skills than children with unilateral CIs because those with bilateral CIs have better speech perception abilities in noisy environments and higher levels of central auditory system development than those with unilateral CIs.

BACKGROUND

Previous studies have focused on the performance of children with bilateral CIs on standardized clinical assessments. However, these tests are not sufficiently sensitive to explain better speech and language outcomes in children with bilateral CIs than children with unilateral CIs. Thus, this study focused on phonological processing skills at more central levels of analysis that reflect the operation of cognitive processes.

METHOD

Twenty children with bilateral CIs and 20 children with unilateral CIs, aged 4 to 6 years, participated in this study. The children completed the experience-dependent tasks and phonological processing tasks. The experience-dependent tasks involved the monosyllabic word, articulation, and receptive vocabulary tests. The phonological processing tasks involved the phonological awareness, phonological memory, and rapid automatic naming tasks. Task performance was compared between the unilateral and bilateral CI groups.

RESULTS

Children with unilateral CIs performed similarly to children with bilateral CIs on all three experience-dependent tasks. However, children with bilateral CIs significantly outperformed children with unilateral CIs on all three phonological processing tasks. Among the phonological processing tasks, the rapid automatic naming task scores differentiated children with unilateral CIs from children with bilateral CIs.

CONCLUSIONS

Bilateral cochlear implantation may positively impact the phonological processing skills of deaf children.

Spoken Word Learning in Children With Developmental Language Disorder or Dyslexia

Purpose Word learning difficulties have been documented in multiple studies involving children with dyslexia and developmental language disorder (DLD; see also specific language impairment). However, no previous studies have directly contrasted word learning in these two frequently co-occurring disorders. We examined word learning in second-grade students with DLD-only and dyslexia-only as compared to each other, peers with both disorders (DLD + dyslexia), and peers with typical development. We hypothesized that children with dyslexia-only and DLD-only would show differences in word learning due to differences in their core language strengths and weaknesses. Method Children (N = 244) were taught eight novel pseudowords paired with unfamiliar objects. The teaching script included multiple exposures to the phonological form, the pictured object, a verbal semantic description of the object, and spaced retrieval practice opportunities. Word learning was assessed immediately after instruction with tasks requiring recall or recognition of the phonological and semantic information. Results Children with dyslexia-only performed significantly better on existing vocabulary measures than their peers with DLD-only. On experimental word learning measures, children in the dyslexia-only and DLD + dyslexia groups showed significantly poorer performance than typically developing children on all word learning tasks. Children with DLD-only differed significantly from the TD group on a single word learning task assessing verbal semantic recall. Conclusions Overall, results indicated that children with dyslexia display broad word learning difficulties extending beyond the phonological domain; however, this contrasted with their relatively strong performance on measures of existing vocabulary knowledge. More research is needed to understand relations between word learning abilities and overall vocabulary knowledge and how to close vocabulary gaps for children with both disorders. Supplemental Material https://doi.org/10.23641/asha.14832717.

ERP Mismatch Negativity Amplitude and Asymmetry Reflect Phonological and Rapid Automatized Naming Skills in English-Speaking Kindergartners

The mismatch negativity (MMN), an electrophysiological response to an oddball auditory stimulus, is related to reading ability in many studies. There are conflicting findings regarding exactly how the MMN relates to risk or actual diagnosis of dyslexia/reading impairment, perhaps due to the heterogeneity of abilities in children with reading impairment. In this study, 166 English-speaking kindergarten children oversampled for dyslexia risk completed behavioral assessments and a speech-syllable MMN paradigm. We examined how early and late MMN mean amplitude and laterality were related to two established predictors of reading ability: phonological awareness (PA) and rapid automatized naming (RAN). In bootstrapped group analyses, late MMN amplitude was significantly greater in children with typical PA ability than low PA ability. In contrast, laterality of the early and late MMN was significantly different in children with low versus typical RAN ability. Continuous analyses controlling for child age, non-verbal IQ, and letter and word identification abilities showed the same associations between late MMN amplitude with PA and late MMN laterality with RAN. These findings suggest that amplitude of the MMN may relate to phonological representations and ability to manipulate them, whereas MMN laterality may reflect differences in brain processes that support automaticity needed for reading.

A Bridge over Troubled Listening: Improving Speech-in-Noise Perception by Children with Dyslexia

Developmental dyslexia is most commonly associated with phonological processing difficulties. However, children with dyslexia may experience poor speech-in-noise perception as well. Although there is an ongoing debate whether a speech perception deficit is inherent to dyslexia or acts as an aggravating risk factor compromising learning to read indirectly, improving speech perception might boost reading-related skills and reading acquisition. In the current study, we evaluated advanced speech technology as applied in auditory prostheses, to promote and eventually normalize speech perception of school-aged children with dyslexia, i.e., envelope enhancement (EE). The EE strategy automatically detects and emphasizes onset cues and consequently reinforces the temporal structure of the speech envelope. Our results confirmed speech-in-noise perception difficulties by children with dyslexia. However, we found that exaggerating temporal "landmarks" of the speech envelope (i.e., amplitude rise time and modulations)-by using EE-passively and instantaneously improved speech perception in noise for children with dyslexia. Moreover, the benefit derived from EE was large enough to completely bridge the initial gap between children with dyslexia and their typical reading peers. Taken together, the beneficial outcome of EE suggests an important contribution of the temporal structure of the envelope to speech perception in noise difficulties in dyslexia, providing an interesting foundation for future intervention studies based on auditory and speech rhythm training.

Structural neural correlates of individual differences in categorical perception

Listeners perceive speech sounds categorically. While group-level differences in categorical perception have been observed in children or individuals with reading disorders, recent findings suggest that typical adults vary in how categorically they perceive sounds. The current study investigated neural sources of individual variability in categorical perception of speech. Fifty-seven participants rated phonetic tokens on a visual analogue scale; categoricity and response consistency were measured and related to measures of brain structure from MRI. Increased surface area of the right middle frontal gyrus predicted more categorical perception of a fricative continuum. This finding supports the idea that frontal regions are sensitive to phonetic category-level information and extends it to make behavioral predictions at the individual level. Additionally, more gyrification in bilateral transverse temporal gyri predicted less consistent responses on the task, perhaps reflecting subtle variation in language ability across the population.

Vowel dyslexia in Turkish: A window to the complex structure of the sublexical route

We report on developmental vowel dyslexia, a type of dyslexia that selectively affects the reading aloud of vowel letters. We identified this dyslexia in 55 Turkish-readers aged 9-10, and made an in-depth multiple-case analysis of the reading of 17 participants whose vowel dyslexia was relatively selective. These participants made significantly more vowel errors (vowel substitution, omission, migration, and addition) than age-matched controls, and significantly more errors in vowel letters than in consonants. Vowel harmony, a pivotal property of Turkish phonology, was intact and the majority of their vowel errors yielded harmonic responses. The transparent character of Turkish orthography indicates that vowel dyslexia is not related to ambiguity in vowel conversion. The dyslexia did not result from a deficit in the phonological-output stage, as the participants did not make vowel errors in nonword repetition or in repeating words they had read with a vowel error. The locus of the deficit was not in the orthographic-visual-analyzer either, as their same-different decision on words differing in vowels was intact, and so was their written-word comprehension. They made significantly more errors on nonwords than on words, indicating that their deficit was in vowel processing in the sublexical route. Given that their single-vowels conversion was intact, and that they showed an effect of the number of vowels, we conclude that their deficit is in a vowel-specific buffer in the sublexical route. They did not make vowel errors within suffixes, indicating that suffixes are converted as wholes in a separate sublexical sub-route. These results have theoretical implications for the dual-route model: they indicate that the sublexical route converts vowels and consonants separately, that the sublexical route includes a vowel buffer, and a separate morphological conversion route. The results also indicate that types of dyslexia can be detected in transparent languages given detailed error-analysis and dyslexia-relevant stimuli.

Timing anticipation in adults and children with Developmental Dyslexia: evidence of an inefficient mechanism

Developmental Dyslexia (DD) is a learning disorder characterized by specific difficulties in learning to read accurately and fluently, which has been generally explained in terms of phonological deficits. Recent research has shown that individuals with DD experience timing difficulties in the domains of language, music perception and motor control, probably due to impaired rhythmic perception, suggesting that timing deficit might be a key underlying factor to explain such a variety of difficulties. The present work presents two experiments aimed at assessing the anticipatory ability on a given rhythm of 9-year old Italian children and Italian adults with and without DD. Both adults and children with DD displayed a greater timing error and were more variable than controls in high predictable stimuli. No difference between participants with and without DD was found in the control condition, in which the uncertain timing of the beat did not permit the extraction of regularities. These results suggest that both children and adults with DD are unable to exploit temporal regularities to efficiently anticipate the next sensory event whereas control participants easily are. By showing that the anticipatory timing system of individuals with Developmental Dyslexia appears affected, this study adds another piece of evidence to the multifaceted reality of Developmental Dyslexia.

Morphological Supports: Investigating Differences in How Morphological Knowledge Supports Reading Comprehension for Middle School Students With Limited Reading Vocabulary

Purpose The current study takes a practical and theoretically grounded look at assessment of morphological knowledge and its potential to deepen understanding of how morphological knowledge supports reading comprehension for students with limited reading vocabulary. Specifically, we explore how different morphological skills support reading comprehension for students with typical reading vocabulary development compared to students with limited reading vocabulary. Method A sample of 1,140 fifth through eighth graders were assessed via a gamified, computer-adaptive measure of language that contained a morphological knowledge assessment. Links to standardized reading comprehension were explored with a focus on determining differences for the 184 students in the sample who showed limited reading vocabulary knowledge. Specifically, multiple regression analyses were used to test for the relation between morphology skills and standardized reading comprehension, as well as the moderator effect of reading vocabulary on the relation between morphological knowledge and standardized reading comprehension. Results Findings indicate that the four instructionally malleable morphological skills identified by the assessment differentially supported reading comprehension. These skills were (a) Morphological Awareness, (b) Syntactic Morphological Knowledge, (c) Semantic Morphological Knowledge, and (d) Phonological/Orthographic Morphological Knowledge. Significant interactions for students with limited reading vocabulary were shown in how the skills of Syntactic Morphological Knowledge, Semantic Morphological Knowledge, and Phonological/Orthographic Morphological Knowledge supported standardized Reading Comprehension. Conclusions Given the challenges students with limited reading vocabulary have with semantic information, Syntactic Morphological Knowledge and Phonological/Orthographic Morphological Knowledge were particularly supportive, suggesting the compensatory role of these morphological skills. In contrast, Semantic Morphological Knowledge had a negative relationship with Reading Comprehension for students with limited reading vocabulary. Implications for theory, research, and practice are discussed.

Differential activation of the visual word form area during auditory phoneme perception in youth with dyslexia

Developmental dyslexia is a learning disorder characterized by difficulties reading words accurately and/or fluently. Several behavioral studies have suggested the presence of anomalies at an early stage of phoneme processing, when the complex spectrotemporal patterns in the speech signal are analyzed and assigned to phonemic categories. In this study, fMRI was used to compare brain responses associated with categorical discrimination of speech syllables (P) and acoustically matched nonphonemic stimuli (N) in children and adolescents with dyslexia and in typically developing (TD) controls, aged 8-17 years. The TD group showed significantly greater activation during the P condition relative to N in an area of the left ventral occipitotemporal cortex that corresponds well with the region referred to as the "visual word form area" (VWFA). Regression analyses using reading performance as a continuous variable across the full group of participants yielded similar results. Overall, the findings are consistent with those of previous neuroimaging studies using print stimuli in individuals with dyslexia that found reduced activation in left occipitotemporal regions; however, the current study shows that these activation differences seen during reading are apparent during auditory phoneme discrimination in youth with dyslexia, suggesting that the primary deficit in at least a subset of children may lie early in the speech processing stream and that categorical perception may be an important target of early intervention in children at risk for dyslexia.

Effects of Noise on the Behavioral and Neural Categorization of Speech

We investigated whether the categorical perception (CP) of speech might also provide a mechanism that aids its perception in noise. We varied signal-to-noise ratio (SNR) [clear, 0 dB, -5 dB] while listeners classified an acoustic-phonetic continuum (/u/ to /a/). Noise-related changes in behavioral categorization were only observed at the lowest SNR. Event-related brain potentials (ERPs) differentiated category vs. category-ambiguous speech by the P2 wave (~180-320 ms). Paralleling behavior, neural responses to speech with clear phonetic status (i.e., continuum endpoints) were robust to noise down to -5 dB SNR, whereas responses to ambiguous tokens declined with decreasing SNR. Results demonstrate that phonetic speech representations are more resistant to degradation than corresponding acoustic representations. Findings suggest the mere process of binning speech sounds into categories provides a robust mechanism to aid figure-ground speech perception by fortifying abstract categories from the acoustic signal and making the speech code more resistant to external interferences.

Morphological processing influences on dyslexia in Greek-speaking children

The study explored the inflectional morphological awareness of Greek-speaking children with dyslexia in grade 3. The sample consisted of 24 dyslexic children and 32 chronological age-matched typically developing readers. All participants completed two oral experimental tasks of inflectional morphological awareness (i.e., verb inflections and noun-adjective inflections). The noun-adjective inflection task assessed children's ability to produce the plural of articles, adjectives, and nouns in the context of a sentence. The verb inflection task required children to change the tense of the verb in a sentence. Furthermore, phonological awareness and oral receptive vocabulary were assessed. Greek-speaking children with dyslexia faced difficulties in both inflectional tasks and in receptive vocabulary. They appeared to have greater difficulty in elicitation of non-past tense from past tense. Binary logistic regression targeted at understanding whether dyslexia can be predicted based on phonological and non-phonological oral language skills revealed that phonological awareness had a significant effect on distinguishing dyslexics from typically developing readers. Overall, our findings lead us to suggest that in an alphabetic language with a shallow orthographic system and rich morphology, children with dyslexia appear to have impaired inflectional morphological awareness and impaired vocabulary in comparison to their peers. Moreover, these results suggest the significance of teaching morphological skills in improving reading skills. However, further research is needed to substantiate these findings.

The effects of high versus low talker variability and individual aptitude on phonetic training of Mandarin lexical tones

High variability (HV) training has been found to be more effective than low variability (LV) training when learning various non-native phonetic contrasts. However, little research has considered whether this applies to the learning of tone contrasts. The only two relevant studies suggested that the effect of HV training depends on the perceptual aptitude of participants (Perrachione et al., 2011; Sadakata & McQueen, 2014). The present study extends these findings by examining the interaction between individual aptitude and input variability using natural, meaningful second language input (both previous studies used pseudowords). A total of 60 English speakers took part in an eight session phonetic training paradigm. They were assigned to high/low/high-blocked variability training groups and learned real Mandarin tones and words. Individual aptitude was measured following previous work. Learning was measured using one discrimination task, one identification task and two production tasks. All tasks assessed generalization. All groups improved in both the production and perception of tones which transferred to untrained voices and items, demonstrating the effectiveness of training despite the increased complexity compared with previous research. Although the LV group exhibited an advantage with the training stimuli, there was no evidence for a benefit of high-variability in any of the tests of generalisation. Moreover, although aptitude significantly predicted performance in discrimination, identification and training tasks, no interaction between individual aptitude and variability was revealed. Additional Bayes Factor analyses indicated substantial evidence for the null for the hypotheses of a benefit of high-variability in generalisation, however the evidence regarding the interaction was ambiguous. We discuss these results in light of previous findings.

Identifying Children at Risk for Developmental Language Disorder Using a Brief, Whole-Classroom Screen

Purpose The aim of this study was to determine whether parents of children with developmental language disorder (DLD) were aware of their children's language difficulties and whether a brief, classroom-based language screen can reliably identify children at risk for DLD, including those with both good and poor word reading skills. Method First- and second-grade students ( N = 97) completed a language screen and assessments of nonverbal intelligence, word reading, and language designed for linguistically diverse students. Their parents completed a questionnaire. Results Few parents of children with DLD reported that their child had ever received speech, language, reading, or other educational services. Parents of children with DLD with average word reading skills reported receiving services approximately half as often as children with DLD with poor word reading. Parents of children with DLD also reported few concerns about their children's speech, language, and academic development. The brief whole-classroom screen showed acceptable classification accuracy for identifying children with DLD overall, although sensitivity was lower for children with DLD with average word reading skills. Conclusion Based on reports of prior services and concerns, many parents of children with DLD appear to be unaware of their children's difficulty with oral language. Whole-classroom screens for language show potential for efficient identification of children who may benefit from comprehensive assessments for DLD without relying on their parents or teachers to raise concerns.

Reading-Induced Shifts in Speech Perception in Dyslexic and Typically Reading Children

One of the proposed mechanisms underlying reading difficulties observed in developmental dyslexia is impaired mapping of visual to auditory speech representations. We investigate these mappings in 20 typically reading and 20 children with dyslexia aged 8–10 years using text-based recalibration. In this paradigm, the pairing of visual text and ambiguous speech sounds shifts (recalibrates) the participant’s perception of the ambiguous speech in subsequent auditory-only post-test trials. Recent research in adults demonstrated this text-induced perceptual shift in typical, but not in dyslexic readers. Our current results instead show significant text-induced recalibration in both typically reading children and children with dyslexia. The strength of this effect was significantly linked to the strength of perceptual adaptation effects in children with dyslexia but not typically reading children. Furthermore, additional analyses in a sample of typically reading children of various reading levels revealed a significant link between recalibration and phoneme categorization. Taken together, our study highlights the importance of considering dynamic developmental changes in reading, letter-speech sound coupling and speech perception when investigating group differences between typical and dyslexic readers.

Independence of syntactic and phonological deficits in dyslexia: A study using the attraction error paradigm

This paper addresses the question of whether dyslexic children suffer from syntactic deficits that are independent of limitations with phonological processing. We looked at subject-verb agreement errors after sentence subjects containing a second noun (the attractor) known to be able to attract incorrect agreement (e.g., "the owner(s) of the house(s) is/are away"). In the general population, attraction errors are not straightforwardly dependent on the presence or absence of morphophonological plural markers but on their syntactic configuration. The same would be expected for dyslexic children if their syntactic problems are not phonological in nature. We also looked at the possible effect of system overload on syntactic processing by comparing auditory and written presentation of stimuli and stimuli with high and low frequency attractors. Dyslexic children produced more agreement errors than age-matched controls, but their errors were distributed in the expected manner and did not align with the presence of morphophonological number markers in the subject overall. Furthermore, there was no effect of either presentation mode or attractor frequency on the number of agreement errors. Our results confirm the existence of syntactic difficulties in dyslexia and suggest that they are not due to a phonological deficit or to verbal working memory limitations.

Cracking the Code: The Impact of Orthographic Transparency and Morphological-Syllabic Complexity on Reading and Developmental Dyslexia

Reading is an essential skill in modern societies, yet not all learners necessarily become proficient readers. Theoretical concepts (e.g., the orthographic depth hypothesis; the grain size theory) as well as empirical evidence suggest that certain orthographies are easier to learn than others. The present paper reviews the literature on orthographic transparency, morphological complexity, and syllabic complexity of alphabetic languages. These notions are elaborated to show that differences in reading acquisition reflect fundamental differences in the nature of the phonological recoding and reading strategies developing in response to the specific orthography to be learned. The present paper provides a narrative, cross-linguistic and integrated literature review, thereby contributing to the development of universal reading models and at the same time pointing out the important differences between orthographies at the more detailed level. Our review also yields suggestions to devise language-specific instruction and interventions for the development of the specific reading strategies required by the characteristics of the orthography being acquired.

Longitudinal relationships between speech perception, phonological skills and reading in children at high-risk of dyslexia

Speech perception deficits are commonly reported in dyslexia but longitudinal evidence that poor speech perception compromises learning to read is scant. We assessed the hypothesis that phonological skills, specifically phoneme awareness and RAN, mediate the relationship between speech perception and reading. We assessed longitudinal predictive relationships between categorical speech perception, phoneme awareness, RAN, language, attention and reading at ages 5½ and 6½ years in 237 children many of whom were at high risk of reading difficulties. Speech perception at 5½ years correlated with language, attention, phoneme awareness and RAN concurrently and was a predictor of reading at 6½ years. There was no significant indirect effect of speech perception on reading via phoneme awareness, suggesting that its effects are separable from those of phoneme awareness. Children classified with dyslexia at 8 years had poorer speech perception than age-controls at 5½ years and children with language disorders (with or without dyslexia) had more severe difficulties with both speech perception and attention control. Categorical speech perception tasks tap factors extraneous to perception, including decision-making skills. Further longitudinal studies are needed to unravel the complex relationships between categorical speech perception tasks and measures of reading and language and attention.

Reading ability and phoneme categorization

Dyslexia is associated with abnormal performance on many auditory psychophysics tasks, particularly those involving the categorization of speech sounds. However, it is debated whether those apparent auditory deficits arise from (a) reduced sensitivity to particular acoustic cues, (b) the difficulty of experimental tasks, or (c) unmodeled lapses of attention. Here we investigate the relationship between phoneme categorization and reading ability, with special attention to the nature of the cue encoding the phoneme contrast (static versus dynamic), differences in task paradigm difficulty, and methodological details of psychometric model fitting. We find a robust relationship between reading ability and categorization performance, show that task difficulty cannot fully explain that relationship, and provide evidence that the deficit is not restricted to dynamic cue contrasts, contrary to prior reports. Finally, we demonstrate that improved modeling of behavioral responses suggests that performance does differ between children with dyslexia and typical readers, but that the difference may be smaller than previously reported.

Early Identification of Dyslexia: Understanding the Issues

Purpose

The purpose of this tutorial is to provide an overview of the benefits and challenges associated with the early identification of dyslexia.

Method

The literature on the early identification of dyslexia is reviewed. Theoretical arguments and research evidence are summarized. An overview of response to intervention as a method of early identification is provided, and the benefits and challenges associated with it are discussed. Finally, the role of speech-language pathologists in the early identification process is addressed.

Conclusions

Early identification of dyslexia is crucial to ensure that children are able to maximize their educational potential, and speech-language pathologists are well placed to play a role in this process. However, early identification alone is not sufficient—difficulties with reading may persist or become apparent later in schooling. Therefore, continuing progress monitoring and access to suitable intervention programs are essential.

Remapping the cognitive and neural profiles of children who struggle at school

Our understanding of learning difficulties largely comes from children with specific diagnoses or individuals selected from community/clinical samples according to strict inclusion criteria. Applying strict exclusionary criteria overemphasizes within group homogeneity and between group differences, and fails to capture comorbidity. Here, we identify cognitive profiles in a large heterogeneous sample of struggling learners, using unsupervised machine learning in the form of an artificial neural network. Children were referred to the Centre for Attention Learning and Memory (CALM) by health and education professionals, irrespective of diagnosis or comorbidity, for problems in attention, memory, language, or poor school progress (n = 530). Children completed a battery of cognitive and learning assessments, underwent a structural MRI scan, and their parents completed behavior questionnaires. Within the network we could identify four groups of children: (a) children with broad cognitive difficulties, and severe reading, spelling and maths problems; (b) children with age-typical cognitive abilities and learning profiles; (c) children with working memory problems; and (d) children with phonological difficulties. Despite their contrasting cognitive profiles, the learning profiles for the latter two groups did not differ: both were around 1 SD below age-expected levels on all learning measures. Importantly a child’s cognitive profile was not predicted by diagnosis or referral reason. We also constructed whole-brain structural connectomes for children from these four groupings (n = 184), alongside an additional group of typically developing children (n = 36), and identified distinct patterns of brain organization for each group. This study represents a novel move toward identifying data-driven neurocognitive dimensions underlying learning-related difficulties in a representative sample of poor learners.

Contextual Influences on Phonetic Categorization in School-Aged Children

Perceptual stability in adult listeners is supported by the ability to process acoustic-phonetic variation categorically and dynamically adjust category boundaries given systematic contextual influences. The current study examined the developmental trajectory of such flexibility. Adults and school-aged children (5-10 years of age) made voicing identification decisions to voice-onset-time (VOT) continua that differed in speaking rate and place of articulation. The results showed that both populations were sensitive to contextual influences; the voicing boundary was located at a longer VOT for the slow compared to the fast speaking rate continuum and for the velar compared to the labial continuum, and the magnitude of the displacement was slighter greater for the adults compared to the children. Moreover, the two populations differed in terms of the absolute location of the voicing boundaries and the categorization slopes, with slopes becoming more categorical as age increased. These results demonstrate that sensitivity to contextual influences on speech perception emerges early in development, but mature perceptual tuning requires extended experience.

Developmental dyslexia and specific language impairment: distinct syntactic profiles?

Recent work exploring syntax in developmental dyslexia (DD) has identified morphosyntactic deficits, striking parallelisms between children with DD and specific language impairment (SLI). The question remains open if the underlying causes for such deficits are related to difficulties in phonology, which is affected in DD, or to working memory, as has been previously reported for SLI. We focus on the production of third person accusative clitic pronouns (ACC3) and of homophonous definite determiners in French-speaking children with DD and SLI as well as typically developing (TD) controls. If syntactic complexity modulates performance of DD children, as has already been shown for SLI, we predict children with DD to perform significantly worse on ACC3 compared to definite determiners, which are homophonous but syntactically simpler. In addition, if impairment in ACC3 stems from phonology or working memory difficulties, we expect ACC3 performance in both clinical groups to relate to performance on non-word repetition or forward/backward digit spans. We studied 2 groups of 21 children and adolescents, with DD and SLI (7-15 years) and age-matched TD controls. Results reveal significant weaknesses with ACC3 in DD and SLI groups compared to TD controls, but no difficulty for homophonous definite determiners, confirming a deficit relating specifically to syntactic complexity. As for links to phonology and working memory, a single correlation emerged between ACC3 and the backward digit span in SLI, but not in DD, suggesting different underlying sources for syntactic deficits in these populations. Clinical implications of these results are discussed.

Reading deficits in schizophrenia and their relationship to developmental dyslexia: A review

Although schizophrenia and developmental dyslexia are considered distinct disorders in terms of clinical presentation and functional outcome, they both involve disruption in the processes that support skilled reading, including language, auditory perception, visual perception, oculomotor control, and executive function. Further, recent work has proposed a common neurodevelopmental basis for the two disorders, as suggested by genetic and pathophysiological overlap. Thus, these lines of research suggest that reading may be similarly impacted in schizophrenia and dyslexia. In this review, we survey research on reading abilities in individuals with schizophrenia, and review the potential mechanisms underlying reading deficits in schizophrenia that may be shared with those implicated in dyslexia. Elucidating the relationship between reading impairment in schizophrenia and dyslexia could allow for a better understanding of the pathophysiological underpinnings of schizophrenia, and could facilitate remediation of cognitive deficits that impact day-to-day functioning.

Spoken sentence production in college students with dyslexia: working memory and vocabulary effects

BACKGROUND

Individuals with dyslexia demonstrate syntactic difficulties on tasks of language comprehension, yet little is known about spoken language production in this population.

AIMS

To investigate whether spoken sentence production in college students with dyslexia is less proficient than in typical readers, and to determine whether group differences can be attributable to cognitive differences between groups.

METHODS & PROCEDURES

Fifty-one college students with and without dyslexia were asked to produce sentences from stimuli comprising a verb and two nouns. Verb types varied in argument structure and morphological form and nouns varied in animacy. Outcome measures were precision (measured by fluency, grammaticality and completeness) and efficiency (measured by response times). Vocabulary and working memory tests were also administered and used as predictors of sentence production performance.

OUTCOMES & RESULTS

Relative to non-dyslexic peers, students with dyslexia responded significantly slower and produced sentences that were significantly less precise in terms of fluency, grammaticality and completeness. The primary predictors of precision and efficiency were working memory, which differed between groups, and vocabulary, which did not.

CONCLUSIONS & IMPLICATIONS

College students with dyslexia were significantly less facile and flexible on this spoken sentence-production task than typical readers, which is consistent with previous studies of school-age children with dyslexia. Group differences in performance were traced primarily to limited working memory, and were somewhat mitigated by strong vocabulary.

Identifying Children at Risk for Language Impairment or Dyslexia With Group-Administered Measures

PURPOSE

The study aims to determine whether brief, group-administered screening measures can reliably identify second-grade children at risk for language impairment (LI) or dyslexia and to examine the degree to which parents of affected children were aware of their children's difficulties.

METHOD

Participants (N = 381) completed screening tasks and assessments of word reading, oral language, and nonverbal intelligence. Their parents completed questionnaires that inquired about reading and language development.

RESULTS

Despite considerable overlap in the children meeting criteria for LI and dyslexia, many children exhibited problems in only one domain. The combined screening tasks reliably identified children at risk for either LI or dyslexia (area under the curve = 0.842), but they were more accurate at identifying risk for dyslexia than LI. Parents of children with LI and/or dyslexia were frequently unaware of their children's difficulties. Parents of children with LI but good word reading skills were the least likely of all impairment groups to report concerns or prior receipt of speech, language, or reading services.

CONCLUSIONS

Group-administered screens can identify children at risk of LI and/or dyslexia with good classification accuracy and in less time than individually administered measures. More research is needed to improve the identification of children with LI who display good word reading skills.

Speech Perception Deficits in Mandarin-Speaking School-Aged Children with Poor Reading Comprehension

Previous studies have shown that children learning alphabetic writing systems who have language impairment or dyslexia exhibit speech perception deficits. However, whether such deficits exist in children learning logographic writing systems who have poor reading comprehension remains uncertain. To further explore this issue, the present study examined speech perception deficits in Mandarin-speaking children with poor reading comprehension. Two self-designed tasks, consonant categorical perception task and lexical tone discrimination task were used to compare speech perception performance in children (n = 31, age range = 7;4-10;2) with poor reading comprehension and an age-matched typically developing group (n = 31, age range = 7;7-9;10). Results showed that the children with poor reading comprehension were less accurate in consonant and lexical tone discrimination tasks and perceived speech contrasts less categorically than the matched group. The correlations between speech perception skills (i.e., consonant and lexical tone discrimination sensitivities and slope of consonant identification curve) and individuals' oral language and reading comprehension were stronger than the correlations between speech perception ability and word recognition ability. In conclusion, the results revealed that Mandarin-speaking children with poor reading comprehension exhibit less-categorized speech perception, suggesting that imprecise speech perception, especially lexical tone perception, is essential to account for reading learning difficulties in Mandarin-speaking children.

Visual artificial grammar learning in dyslexia: A meta-analysis

BACKGROUND

Literacy impairments in dyslexia have been hypothesized to be (partly) due to an implicit learning deficit. However, studies of implicit visual artificial grammar learning (AGL) have often yielded null results.

AIMS

The aim of this study is to weigh the evidence collected thus far by performing a meta-analysis of studies on implicit visual AGL in dyslexia.

METHODS AND PROCEDURES

Thirteen studies were selected through a systematic literature search, representing data from 255 participants with dyslexia and 292 control participants (mean age range: 8.5-36.8 years old).

RESULTS

If the 13 selected studies constitute a random sample, individuals with dyslexia perform worse on average than non-dyslexic individuals (average weighted effect size=0.46, 95% CI [0.14 … 0.77], p=0.008), with a larger effect in children than in adults (p=0.041; average weighted effect sizes 0.71 [sig.] versus 0.16 [non-sig.]). However, the presence of a publication bias indicates the existence of missing studies that may well null the effect.

CONCLUSIONS AND IMPLICATIONS

While the studies under investigation demonstrate that implicit visual AGL is impaired in dyslexia (more so in children than in adults, if in adults at all), the detected publication bias suggests that the effect might in fact be zero.

The Effects of Phonological Short-Term Memory and Speech Perception on Spoken Sentence Comprehension in Children: Simulating Deficits in an Experimental Design

The roles of phonological short-term memory (pSTM) and speech perception in spoken sentence comprehension were examined in an experimental design. Deficits in pSTM and speech perception were simulated through task demands while typically-developing children (N [Formula: see text] 71) completed a sentence-picture matching task. Children performed the control, simulated pSTM deficit, simulated speech perception deficit, or simulated double deficit condition. On long sentences, the double deficit group had lower scores than the control and speech perception deficit groups, and the pSTM deficit group had lower scores than the control group and marginally lower scores than the speech perception deficit group. The pSTM and speech perception groups performed similarly to groups with real deficits in these areas, who completed the control condition. Overall, scores were lowest on noncanonical long sentences. Results show pSTM has a greater effect than speech perception on sentence comprehension, at least in the tasks employed here.