Visual attentional engagement deficits in children with specific language impairment and their role in real-time language processing

Lexical-semantic processing in preschoolers with Developmental Language Disorder: an eye tracking study

This study examined lexical-semantic processing in children with Developmental Language Disorder (DLD) during visually situated comprehension of real-time spoken words. Existing evidence suggests that children with DLD may experience challenges in lexical access and retrieval, as well as greater lexical competition compared to their peers with Typical Development (TD). However, the specific nature of these difficulties remains unclear. Using eye-tracking methodology, the study investigated the real-time comprehension of semantic relationships in children with DLD and their age-matched peers. The results revealed that, for relatively frequent nouns, both groups demonstrated similar comprehension of semantic relationships. Both groups favored the semantic competitor when it appeared with an unrelated visual referent. In turn, when the semantic competitor appeared with the visual referent of the spoken word, both groups disregarded the competitor. This finding shows that, although children with DLD usually present a relatively impoverished vocabulary, frequent nouns may not pose greater difficulties for them. While the temporal course of preference for the competitor or the referent was similar between the two groups, numerical, though non-significant, differences in the extension of the clusters were observed. In summary, this research demonstrates that monolingual preschoolers with DLD exhibit similar lexical access to frequent words compared to their peers with TD. Future studies should investigate the performance of children with DLD on less frequent words to provide a comprehensive understanding of their lexical-semantic abilities.

The Lexicon and Morphosyntax of Child Spanish as Predictors of Inhibition

This study investigates the relationships between lexical development and inhibition, as well as morphosyntax and inhibition, in typically developing monolingual Spanish-speaking children. Recent studies of the relationship between lexical development and inhibition suggest that, as the size of the lexicon increases, so does inhibitory ability. However, the relationship between grammar and inhibition seems more controversial. The work distinguishing the relationships between inhibition and lexicon vs. grammar have been carried out in English, which has relatively impoverished inflectional morphology. Because the relationships considered in the literature are hypothetically not language-particular to English, but rather claims about cognition in general, we would expect to find that they also hold in other languages, including languages with richer morphology, such as Spanish. These considerations led us to ask the following: are expressive and receptive measures of the lexicon and morphosyntax predictive of typically developing monolingual child Spanish-speakers' inhibitory ability? A sample of 82 monolingual, typically developing Spanish-speaking children in Mexico City were tested with 5 lexical measures, 4 morphosyntax measures, and the Flanker Task measure of inhibition. Results showed that all lexical and morphosyntactic variables correlated significantly with Flanker (p < 0.01), except for Number of Different Words (NDW), calculated on the spontaneous production sample. Therefore, inhibition is predicted by lexical development in child Spanish. Additionally, an ever-increasing set of competitor morphological forms requires an ever-increasing inhibitory ability as well.

Nonverbal Executive Functioning in Relation to Vocabulary and Morphosyntax in Preschool Children With and Without Developmental Language Disorder

PURPOSE

Developmental language disorder (DLD) is characterized by persistent and unexplained difficulties in language development. Accumulating evidence shows that children with DLD also present with deficits in other cognitive domains, such as executive functioning (EF). There is an ongoing debate on whether exclusively verbal EF abilities are impaired in children with DLD or whether nonverbal EF is also impaired, and whether these EF impairments are related to their language difficulties. The aims of this study were to (a) compare nonverbal performance of preschoolers with DLD and typically developing (TD) peers, (b) examine how nonverbal EF and language abilities are related, and (c) investigate whether a diagnosis of DLD moderates the relationship between EF and language abilities.

METHOD

A total of 143 children (nDLD = 65, nTD = 78) participated. All children were between 3 and 6.5 years old and were monolingual Dutch. We assessed nonverbal EF with a visual selective attention task, a visuospatial short-term and working memory task, and a task gauging broad EF abilities. Vocabulary and morphosyntax were each measured with two standardized language tests. We created latent variables for EF, vocabulary, and morphosyntax.

RESULTS

Analyses showed that children with DLD were outperformed by their TD peers on all nonverbal EF tasks. Nonverbal EF abilities were related to morphosyntactic abilities in both groups, whereas a relationship between vocabulary and EF skills was found in the TD group only. These relationships were not significantly moderated by a diagnosis of DLD.

CONCLUSIONS

We found evidence for nonverbal EF impairments in preschool children with DLD. Moreover, nonverbal EF and morphosyntactic abilities were significantly related in these children. These findings may have implications for intervention and support the improvement of prognostic accuracy.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24121287.

Are items actively removed from working memory during free time in children with developmental language disorder?

BACKGROUND

Children with developmental language disorder (DLD) have deficits in verbal and non-verbal processing relative to typically developing (TD) peers, potentially reflecting difficulties in working memory, processing speed and inhibition of interference. We examined working memory in children with DLD using the serial-order-in-a-box-complex span (SOB-CS) interference-based model, which posits a time-based mechanism, free time, that governs how interference affects processing performance.

AIMS

(1) To determine the degree to which children with DLD and TD children differ in the amount of free time available during working memory tasks, and whether potential group differences in free time differ depending on the domain of task demands? (2) To determine the relationship between free time and interference effects on working memory accuracy in children with DLD relative to TD peers.

METHODS & PROCEDURES

We examined the relationship between free time and working memory in children aged 9-13 years with DLD relative to age-matched TD peers. Working memory tasks involved five conditions that varied verbal versus non-verbal task demands in an interference processing phase relative to a recall test phase. Free time was the time between response on the interference processing task and onset of the recall test phase.

OUTCOMES & RESULTS

DLD and TD groups did not differ in total free time in any condition. Results indicated group differences in the relationship between free time and accuracy in the conditions involving verbal recall, but not non-verbal recall. In the verbal-only condition, relatively more free time was associated with worse accuracy for the DLD group, but with better accuracy for the TD group. In the condition with verbal recall paired with non-verbal interference processing, relatively more free time was associated with better accuracy for the DLD group, but not for the TD group.

CONCLUSIONS & IMPLICATIONS

The overall findings suggest that free time between cognitive operations is positively associated with working memory for both verbal and non-verbal recall, except in the presence of high verbal interference for the DLD group (i.e., verbal interference paired with verbal recall). This finding may reflect poor encoding and attention under particularly challenging verbal processing demands for the DLD group. This study also demonstrates the importance of considering the interrelationships between processing speed and interference in working memory performance.

WHAT THIS PAPER ADDS

What is already known on the subject DLD is characterized by core deficits in verbal processing, but also deficits in non-verbal processing. Processing-based hypotheses of DLD-limited verbal working memory, slowed processing speed and inefficient inhibition-do not fully account for behavioural profiles in DLD when considered separately, yet there is evidence suggesting interrelationships among these factors. What this paper adds to existing knowledge The current study tests the key mechanism posited by a theoretical framework that has the potential to integrate these processing-based hypotheses. Our findings indicate that the effect of this mechanism differed in DLD relative to TD peers in the presence of high verbal task demands. Our findings also demonstrate the importance of considering the interrelationships among cognitive processes in children with DLD. What are the potential or actual clinical implications of this work? In practice, results from the current study suggest that children with DLD may benefit from supplementing verbal information with non-verbal information and from pauses between successive presentations of verbal information. These strategies may support their ability to maintain and act on information during verbal processing.

Working Memory Performance in Children With Developmental Language Disorder: The Role of Domain

PURPOSE

This study examined working memory in children with developmental language disorder (DLD). The overarching goal of this work was to integrate three primary processing-based hypotheses of DLD, (a) limited verbal working memory, (b) slowed processing speed, and (c) inefficient inhibition of interference, by using the serial-order-in-a-box-complex span (SOB-CS) computational model as our theoretical framework. We also examined the role of domain in working memory performance by varying the domain of interference and recall (i.e., verbal vs. nonverbal) task demands.

METHOD

Participants were 55 school-age children, 21 children with DLD and 34 age-matched typically developing (TD) peers (9-13 years old).

RESULTS

Findings indicated that verbal and nonverbal working memory performance was poorer in the DLD than TD group. There was a modest benefit of dispersing interference and recall task demands across domains relative to task demands being within one domain, yet verbal interference affected performance to a greater degree than nonverbal interference in the DLD group.

CONCLUSIONS

Overall findings supported a role for each of the processing-based hypotheses of DLD, albeit an incomplete role. In contrast, the SOB-CS model accounted for interrelationships among these processing-based factors and provided an explanation across patterns of findings. Thus, the SOB-CS model represents a useful step forward in explaining processing in children with DLD.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19526179.

Do Children With Developmental Language Disorder Activate Scene Knowledge to Guide Visual Attention? Effect of Object-Scene Inconsistencies on Gaze Allocation

Our visual environment is highly predictable in terms of where and in which locations objects can be found. Based on visual experience, children extract rules about visual scene configurations, allowing them to generate scene knowledge. Similarly, children extract the linguistic rules from relatively predictable linguistic contexts. It has been proposed that the capacity of extracting rules from both domains might share some underlying cognitive mechanisms. In the present study, we investigated the link between language and scene knowledge development. To do so, we assessed whether preschool children (age range = 5;4–6;6) with Developmental Language Disorder (DLD), who present several difficulties in the linguistic domain, are equally attracted to object-scene inconsistencies in a visual free-viewing task in comparison with age-matched children with Typical Language Development (TLD). All children explored visual scenes containing semantic (e.g., soap on a breakfast table), syntactic (e.g., bread on the chair back), or both inconsistencies (e.g., soap on the chair back). Since scene knowledge interacts with image properties (i.e., saliency) to guide gaze allocation during visual exploration from the early stages of development, we also included the objects’ saliency rank in the analysis. The results showed that children with DLD were less attracted to semantic and syntactic inconsistencies than children with TLD. In addition, saliency modulated syntactic effect only in the group of children with TLD. Our findings indicate that children with DLD do not activate scene knowledge to guide visual attention as efficiently as children with TLD, especially at the syntactic level, suggesting a link between scene knowledge and language development.

An Integrated Perspective on Spatio-Temporal Attention and Infant Language Acquisition

Efficiency in the early ability to switch attention toward competing visual stimuli (spatial attention) may be linked to future ability to detect rapid acoustic changes in linguistic stimuli (temporal attention). To test this hypothesis, we compared individual performances in the same cohort of Italian-learning infants in two separate tasks: (i) an overlap task, measuring disengagement efficiency for visual stimuli at 4 months (Experiment 1), and (ii) an auditory discrimination task for trochaic syllabic sequences at 7 months (Experiment 2). Our results indicate that an infant's efficiency in processing competing information in the visual field (i.e., visuospatial attention; Exp. 1) correlates with the subsequent ability to orient temporal attention toward relevant acoustic changes in the speech signal (i.e., temporal attention; Exp. 2). These results point out the involvement of domain-general attentional processes (not specific to language or the sensorial domain) playing a pivotal role in the development of early language skills in infancy.

Attentional engagement during syllable discrimination: The role of salient prosodic cues in 6- to 8-month-old infants

Prosodic cues drive speech segmentation and guide syllable discrimination. However, less is known about the attentional mechanisms underlying an infant's ability to benefit from prosodic cues. This study investigated how 6- to 8-month-old Italian infants allocate their attention to strong vs. weak syllables after familiarization with four repeats of a single CV sequence with alternating strong and weak syllables (different syllables on each trial). In the discrimination test-phase, either the strong or the weak syllable was replaced by a pure tone matching the suprasegmental characteristics of the segmental syllable, i.e., duration, loudness and pitch, whereas the familiarized stimulus was presented as a control. By using an eye-tracker, attention deployment (fixation times) and cognitive resource allocation (pupil dilation) were measured under conditions of high and low saliency that corresponded to the strong and weak syllabic changes, respectively. Italian learning infants were found to look longer and also to show, through pupil dilation, more attention to changes in strong syllable replacement rather than weak syllable replacement, compared to the control condition. These data offer insights into the strategies used by infants to deploy their attention towards segmental units guided by salient prosodic cues, like the stress pattern of syllables, during speech segmentation.

Language and Inhibition: Predictive Relationships in Children With Language Impairment Relative to Typically Developing Peers

Background This study examined predictive relationships between two indices of language-receptive vocabulary and morphological comprehension-and inhibition in children with specific language impairment (SLI) and typically developing (TD) children. Methods Participants included 30 children with SLI and 41 TD age-matched peers (8-12 years). At two time points separated by 1 year, we assessed receptive vocabulary and morphological comprehension via standardized language measures and inhibition via a Flanker task. We used Bayesian model averaging and Bayesian regression analytical techniques. Results Findings indicated predictive relationships between language indices and inhibition reaction time (RT), but not between language indices and inhibition accuracy. For the SLI group, Year 1 inhibition RT predicted Year 2 morphological comprehension. For the TD group, Year 1 morphological comprehension predicted Year 2 inhibition RT. Conclusions This study provides preliminary evidence of a predictive relationship between language and inhibition, but this relationship differed between children with SLI and those with typical development. Findings suggest that inhibition RT played a larger predictive role in later morphological comprehension in children with SLI relative to the other relationships examined. Targeting inhibition skills as a part of language intervention may improve subsequent morphological comprehension. Supplemental Material https://doi.org/10.23641/asha.12014823.

The Complex Relation between Executive Functions and Language in Preschoolers with Developmental Language Disorders

Backgrounds: The relationship between linguistic difficulties and cognitive impairments in children with developmental language disorders (DLDs) is receiving growing interest in international research. Executive functions (EF) appear to be weak in these children. The current investigation aims at exploring the relationship between difficulties in two components of EF (i.e., updating and inhibition) and the linguistic and narrative skills of 16 DLD preschoolers matched with 24 typically developing peers. Methods: Updating skills were tested by administering the forward and backward digit recall subtests of the Wechsler Scales, while children's inhibition abilities were assessed by completion of Developmental Neuropsychological Assessment (NEPSY-II) inhibition tasks. Information on the linguistic skills of the participants was collected through a set of subtests included in the Batteria per la Valutazione del Linguaggio in bambini dai 4 ai 12 anni (Batteria per la Valutazione del Linguaggio; BVL_4-12), assessing articulatory and phonological discrimination skills, lexical production/comprehension, grammatical production/comprehension, and narrative production skills. Results: Findings revealed that DLD children performed significantly lower than their peers on both updating and inhibitory tasks. Linguistic difficulties were found in the DLD group on articulatory/phonological skills, grammatical production/comprehension, and lexical informativeness on narrative production. Measures of EF correlated with linguistic and narrative measures. Conclusion: The current study confirms a significant association between DLD's performances on EF and displayed linguistic skills, suggesting the need to include the assessment of executive functions to target early intervention rehabilitation programs for children with DLDs.

Cross-frequency Phase–Amplitude Coupling as a Mechanism for Temporal Orienting of Attention in Childhood

Temporal orienting of attention operates by biasing the allocation of cognitive and motor resources in specific moments in time, resulting in the improved processing of information from expected compared with unexpected targets. Recent findings have shown that temporal orienting operates relatively early across development, suggesting that this attentional mechanism plays a core role for human cognition. However, the exact neurophysiological mechanisms allowing children to attune their attention over time are not well understood. In this study, we presented 8- to 12-year-old children with a temporal cueing task designed to test (1) whether anticipatory oscillatory dynamics predict children's behavioral performance on a trial-by-trial basis and (2) whether anticipatory oscillatory neural activity may be supported by cross-frequency phase–amplitude coupling as previously shown in adults. Crucially, we found that, similar to what has been reported in adults, children's ongoing beta rhythm was strongly coupled with their theta rhythm and that the strength of this coupling distinguished validly cued temporal intervals, relative to neutral cued trials. In addition, in long trials, there was an inverse correlation between oscillatory beta power and children's trial-by-trial reaction, consistent with oscillatory beta power reflecting better response preparation. These findings provide the first experimental evidence that temporal attention in children operates by exploiting oscillatory mechanism.

Sensitivity to Audiovisual Temporal Asynchrony in Children With a History of Specific Language Impairment and Their Peers With Typical Development: A Replication and Follow-Up Study

PURPOSE

Earlier, my colleagues and I showed that children with a history of specific language impairment (H-SLI) are significantly less able to detect audiovisual asynchrony compared with children with typical development (TD; Kaganovich & Schumaker, 2014). Here, I first replicate this finding in a new group of children with H-SLI and TD and then examine a relationship among audiovisual function, attention skills, and language in a combined pool of children.

METHOD

The stimuli were a pure tone and an explosion-shaped figure. Stimulus onset asynchrony (SOA) varied from 0-500 ms. Children pressed 1 button for perceived synchrony and another for asynchrony. I measured the number of synchronous perceptions at each SOA and calculated children's temporal binding windows. I, then, conducted multiple regressions to determine if audiovisual processing and attention can predict language skills.

RESULTS

As in the earlier study, children with H-SLI perceived asynchrony significantly less frequently than children with TD at SOAs of 400-500 ms. Their temporal binding windows were also larger. Temporal precision and attention predicted 23%-37% of children's language ability.

CONCLUSIONS

Audiovisual temporal processing is impaired in children with H-SLI. The degree of this impairment is a predictor of language skills. Once understood, the mechanisms underlying this deficit may become a new focus for language remediation.

Action video games improve reading abilities and visual-to-auditory attentional shifting in English-speaking children with dyslexia

Dyslexia is characterized by difficulties in learning to read and there is some evidence that action video games (AVG), without any direct phonological or orthographic stimulation, improve reading efficiency in Italian children with dyslexia. However, the cognitive mechanism underlying this improvement and the extent to which the benefits of AVG training would generalize to deep English orthography, remain two critical questions. During reading acquisition, children have to integrate written letters with speech sounds, rapidly shifting their attention from visual to auditory modality. In our study, we tested reading skills and phonological working memory, visuo-spatial attention, auditory, visual and audio-visual stimuli localization, and cross-sensory attentional shifting in two matched groups of English-speaking children with dyslexia before and after they played AVG or non-action video games. The speed of words recognition and phonological decoding increased after playing AVG, but not non-action video games. Furthermore, focused visuo-spatial attention and visual-to-auditory attentional shifting also improved only after AVG training. This unconventional reading remediation program also increased phonological short-term memory and phoneme blending skills. Our report shows that an enhancement of visuo-spatial attention and phonological working memory, and an acceleration of visual-to-auditory attentional shifting can directly translate into better reading in English-speaking children with dyslexia.

Visual Attention Processes and Oculomotor Control in Autism Spectrum Disorder: A Brief Review and Future Directions

Autism spectrum disorder (ASD) is defined as persistent deficits in social communication and social interaction, and restricted, repetitive patterns of behavior, interests or activities Diagnostic and Statistical Manual of Mental Disorders (5th ed., DSM-5; American Psychiatric Association, 2013). However, individuals with ASD show clearly atypical visual patterns. So far, indications of abnormal visual attention and oculomotor control concerning stimuli independent of social function in ASD have been found. The same findings have been shown in individuals suffering of other neurodevelopmental disorders (e.g., developmental coordination disorder and developmental dyslexia [DD]). Furthermore, visual attention processes and oculomotor control are supposed to be subserved by the magnocellular visual system, which has been found, in turn, to be dysfunctional in ASD and other neurodevelopmental disabilities (i.e., DD). The purpose of this article is to briefly review the link between oculomotor control and visual attention processes and ASD, and to discuss the specificity and overlap of eye movement findings between ASD and other neurodevelopmental disorders.

Executive Functions in Children With Specific Language Impairment: A Meta-Analysis

PURPOSE

Mounting evidence demonstrates deficits in children with specific language impairment (SLI) beyond the linguistic domain. Using meta-analysis, this study examined differences in children with and without SLI on tasks measuring inhibition and cognitive flexibility.

METHOD

Databases were searched for articles comparing children (4-14 years) with and without SLI on behavioral measures of inhibition or cognitive flexibility. Weighted average effect size was calculated using multilevel modeling to measure potential group differences.

RESULTS

The analysis included 46 studies. Of those, 34 included inhibitory control measures and 22 included cognitive flexibility tasks. Children with SLI performed below same-aged peers on both inhibitory control tasks (g = -.56) and cognitive flexibility tasks (g = -.27). Moderator analyses showed no effect of linguistic task demands, participant age, or severity of language impairment on the degree of difference between children with SLI and controls on measures of inhibitory control.

CONCLUSION

Reliable differences between children with and without SLI were found on inhibition and cognitive flexibility tasks. A moderate group effect was found for inhibition tasks, but there was only a small effect for cognitive flexibility tasks. Results of moderator analyses suggest that these deficits are present throughout development despite task demands or severity of linguistic impairment.

Atypical audiovisual word processing in school-age children with a history of specific language impairment: an event-related potential study

Background

Visual speech cues influence different aspects of language acquisition. However, whether developmental language disorders may be associated with atypical processing of visual speech is unknown. In this study, we used behavioral and ERP measures to determine whether children with a history of SLI (H-SLI) differ from their age-matched typically developing (TD) peers in the ability to match auditory words with corresponding silent visual articulations.

Methods

Nineteen 7–13-year-old H-SLI children and 19 age-matched TD children participated in the study. Children first heard a word and then saw a speaker silently articulating a word. In half of trials, the articulated word matched the auditory word (congruent trials), while in another half, it did not (incongruent trials). Children specified whether the auditory and the articulated words matched. We examined ERPs elicited by the onset of visual stimuli (visual P1, N1, and P2) as well as ERPs elicited by the articulatory movements themselves—namely, N400 to incongruent articulations and late positive complex (LPC) to congruent articulations. We also examined whether ERP measures of visual speech processing could predict (1) children’s linguistic skills and (2) the use of visual speech cues when listening to speech-in-noise (SIN).

Results

H-SLI children were less accurate in matching auditory words with visual articulations. They had a significantly reduced P1 to the talker’s face and a smaller N400 to incongruent articulations. In contrast, congruent articulations elicited LPCs of similar amplitude in both groups of children. The P1 and N400 amplitude was significantly correlated with accuracy enhancement on the SIN task when seeing the talker’s face.

Conclusions

H-SLI children have poorly defined correspondences between speech sounds and visually observed articulatory movements that produce them.

Use of Questionnaire-Based Measures in the Assessment of Listening Difficulties in School-Aged Children

In this study, the authors assessed the potential utility of a recently developed questionnaire (Evaluation of Children’s Listening and Processing Skills [ECLiPS]) for supporting the clinical assessment of children referred for auditory processing disorder (APD).

Questionnaires potentially offer valuable information about everyday listening difficulty in children referred for suspected APD. However, there are many problems with currently available questionnaires. This paper considers the validity and usefulness of a new questionnaire called the Evaluation of Children’s Listening and Processing Skills (ECLiPS) in comparison with three other available questionnaires. All the questionnaires in the study were similarly sensitive to the presence of problems, but the ECLiPS provided clearer evidence of construct validity particularly with respect to measures of cognitive abilities. Discriminant analysis suggested that a combination of ECLiPS factors with auditory and cognitive measures achieved best discrimination among the participant groups in the study.

Spatiotemporally dissociable neural signatures for generating and updating expectation over time in children: A High Density-ERP study

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8–12-year-old children can generate and update expectancy over time.

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Cue- and SOA-related ERPs reflect expectancy generation and updating, respectively.

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Only cue-related ERPs are correlated with age.

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Distinct cortical networks underlie cue- and SOA-related ERP effects.

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The neural bases of temporal expectation only partially differ in children and adults.

Temporal orienting (TO) is the allocation of attentional resources in time based on the a priori generation of temporal expectancy of relevant stimuli as well as the a posteriori updating of this expectancy as a function of both sensory-based evidence and elapsing time. These processes rely on dissociable cognitive mechanisms and neural networks. Yet, although there is evidence that TO may be a core mechanism for cognitive functioning in childhood, the developmental spatiotemporal neural dynamics of this mechanism are little understood. In this study we employed a combined approach based on the application of distributed source reconstruction on a high spatial resolution ERP data array obtained from eighteen 8- to 12-year-old children completing a TO paradigm in which both the cue (Temporal vs. Neutral) and the SOA (Short vs. Long) were manipulated. Results show both cue (N1) and SOA (CNV, Omission Detection Potential and Anterior Anticipatory Index) ERP effects, which were associated with expectancy generation and updating, respectively. Only cue-related effects were correlated with age, as revealed by a reduction of the N1 delta effect with increasing age. Our data suggest that the neural correlates underlying TO are already established at least from 8 to 12 years of age.

The effect of spatio-temporal distance between visual stimuli on information processing in children with Specific Language Impairment

The purpose of this study is to evaluate whether children with Specific Language Impairment (SLI) have a deficit in processing a sequence of two visual stimuli (S1 and S2) presented at different inter-stimulus intervals and in different spatial locations. In particular, the core of this study is to investigate whether S1 identification is disrupted due to a retroactive interference of S2. To this aim, two experiments were planned in which children with SLI and children with typical development (TD), matched by age and non-verbal IQ, were compared (Experiment 1: SLI n=19; TD n=19; Experiment 2: SLI n=16; TD n=16). Results show group differences in the ability to identify a single stimulus surrounded by flankers (Baseline level). Moreover, children with SLI show a stronger negative interference of S2, both for temporal and spatial modulation. These results are discussed in the light of an attentional processing limitation in children with SLI.

Multiple Causal Links Between Magnocellular-Dorsal Pathway Deficit and Developmental Dyslexia

Although impaired auditory-phonological processing is the most popular explanation of developmental dyslexia (DD), the literature shows that the combination of several causes rather than a single factor contributes to DD. Functioning of the visual magnocellular-dorsal (MD) pathway, which plays a key role in motion perception, is a much debated, but heavily suspected factor contributing to DD. Here, we employ a comprehensive approach that incorporates all the accepted methods required to test the relationship between the MD pathway dysfunction and DD. The results of 4 experiments show that (1) Motion perception is impaired in children with dyslexia in comparison both with age-match and with reading-level controls; (2) pre-reading visual motion perception-independently from auditory-phonological skill-predicts future reading development, and (3) targeted MD trainings-not involving any auditory-phonological stimulation-leads to improved reading skill in children and adults with DD. Our findings demonstrate, for the first time, a causal relationship between MD deficits and DD, virtually closing a 30-year long debate. Since MD dysfunction can be diagnosed much earlier than reading and language disorders, our findings pave the way for low resource-intensive, early prevention programs that could drastically reduce the incidence of DD.

Inducing attention not to blink: auditory entrainment improves conscious visual processing

Our ability to allocate attention at different moments in time can sometimes fail to select stimuli occurring in close succession, preventing visual information from reaching awareness. This so-called attentional blink (AB) occurs when the second of two targets (T2) is presented closely after the first (T1) in a rapid serial visual presentation (RSVP). We hypothesized that entrainment to a rhythmic stream of stimuli-before visual targets appear-would reduce the AB. Experiment 1 tested the effect of auditory entrainment by presenting sounds with a regular or irregular interstimulus interval prior to a RSVP where T1 and T2 were separated by three possible lags (1, 3 and 8). Experiment 2 examined visual entrainment by presenting visual stimuli in place of auditory stimuli. Results revealed that irrespective of sensory modality, arrhythmic stimuli preceding the RSVP triggered an alerting effect that improved the T2 identification at lag 1, but impaired the recovery from the AB at lag 8. Importantly, only auditory rhythmic entrainment was effective in reducing the AB at lag 3. Our findings demonstrate that manipulating the pre-stimulus condition can reduce deficits in temporal attention characterizing the human cognitive architecture, suggesting innovative trainings for acquired and neurodevelopmental disorders.

Executive Function in SLI: Recent Advances and Future Directions

This paper provides a review of recent research on executive function abilities in children with specific language impairment (SLI). Across several studies, children with SLI are reported to perform worse than typically developing peers on measures of sustained attention, working memory, inhibition, and attention shifting. However, few studies have considered multiple executive function components simultaneously and even fewer have examined the underlying relationship between executive function deficits and impaired language acquisition. We argue that in order to fully understand the nature of executive function deficits in SLI, the field must move past simply identifying weaknesses to instead test models of executive function development and explore the nature of the relationship between executive function and language. Future research directions are recommended in order to achieve these goals.

Non-word repetition: the relationship between weak syllables and the omission of grammatical morphemes in children with specific language impairment

Non-word (NW) repetition in children with specific language impairment (SLI) is a skill related to, but genetically separate from, grammatical ability. Prosodic structure of the syllables may bridge the gap between these two abilities. A NW repetition task was compared in a group of 15 preschool Italian children with SLI (ranged in age from 3;11 to 5;8) and 15 younger typically developing children (aged from 2;11 to 3;7) matched for mean length of utterance (TD-MLU). Grammatical ability was tested through a probe for direct-object clitic pronouns which is one of the most useful clinical markers in the Italian language. In NW repetition, children with SLI deleted more syllables than the TD-MLU children. The omission of weak syllables in a pre-stress position was a significant predictor of the omission of clitic pronouns. The present study shows that the link between grammar and NW is due to a prosodic characteristic that is more universally challenging in children with SLI.

Children with a history of SLI show reduced sensitivity to audiovisual temporal asynchrony: an ERP study

PURPOSE

The authors examined whether school-age children with a history of specific language impairment (H-SLI), their peers with typical development (TD), and adults differ in sensitivity to audiovisual temporal asynchrony and whether such difference stems from the sensory encoding of audiovisual information.

METHOD

Fifteen H-SLI children, 15 TD children, and 15 adults judged whether a flashed explosion-shaped figure and a 2-kHz pure tone occurred simultaneously. The stimuli were presented at 0-, 100-, 200-, 300-, 400-, and 500-ms temporal offsets. This task was combined with EEG recordings.

RESULTS

H-SLI children were profoundly less sensitive to temporal separations between auditory and visual modalities compared with their TD peers. Those H-SLI children who performed better at simultaneity judgment also had higher language aptitude. TD children were less accurate than adults, revealing a remarkably prolonged developmental course of the audiovisual temporal discrimination. Analysis of early event-related potential components suggested that poor sensory encoding was not a key factor in H-SLI children's reduced sensitivity to audiovisual asynchrony.

CONCLUSIONS

Audiovisual temporal discrimination is impaired in H-SLI children and is still immature during mid-childhood in TD children. The present findings highlight the need for further evaluation of the role of atypical audiovisual processing in the development of SLI.

Spatial and temporal attention in developmental dyslexia

Although the dominant view posits that developmental dyslexia (DD) arises from a deficit in phonological processing, emerging evidence suggest that DD could result from a more basic cross-modal letter-to-speech sound integration deficit. Letters have to be precisely selected from irrelevant and cluttering letters by rapid orienting of visual attention before the correct letter-to-speech sound integration applies. In the present study the time-course of spatial attention was investigated measuring target detection reaction times (RTs) in a cuing paradigm, while temporal attention was investigated by assessing impaired identification of the first of two sequentially presented masked visual objects. Spatial and temporal attention were slower in dyslexic children with a deficit in pseudoword reading (N = 14) compared to chronological age (N = 43) and to dyslexics without a deficit in pseudoword reading (N = 18), suggesting a direct link between visual attention efficiency and phonological decoding skills. Individual differences in these visual attention mechanisms were specifically related to pseudoword reading accuracy in dyslexics. The role of spatial and temporal attention in the graphemic parsing process might be related to a basic oscillatory "temporal sampling" dysfunction.

Clinical markers in Italian-speaking children with and without specific language impairment: a study of non-word and real word repetition as predictors of grammatical ability

BACKGROUND

In many languages a weakness in non-word repetition serves as a useful clinical marker of specific language impairment (SLI) in children. However, recent work in Italian has shown that the repetition of real words may also have clinical utility. For young typically developing Italian children, real word repetition is more predictive of particular grammatical abilities than is non-word repetition. This finding is important because these particular grammatical abilities--the production of present-tense third-person plural inflections and direct-object clitic pronouns--are precisely those that are problematic for Italian-speaking children with SLI. Along with their grammatical requirements, these two morpheme types present a significant phonological/prosodic challenge for these children.

AIMS

To replicate the findings with young typically developing Italian children and to determine whether real word repetition is also more predictive of the use of these two morpheme types than is non-word repetition in a group of Italian-speaking children with SLI.

METHODS & PROCEDURES

Seventeen Italian-speaking children with SLI and 17 younger typically developing children matched for mean length of utterance participated in tasks of real word and non-word repetition as well as tasks requiring the production of direct-object clitic pronouns and present-tense third-person plural inflections.

OUTCOMES & RESULTS

Children with SLI were less accurate than their younger peers on all measures. Importantly, for the younger typically developing children, real word repetition explained a significant amount of variance in the use of third-person plural inflections and direct-object clitic pronouns. For the children with SLI, in contrast, non-word repetition was a significant predictor, whereas real word repetition was not a contributing factor.

CONCLUSIONS & IMPLICATIONS

It is argued that in Italian SLI, the grammatical details showing the greatest weakness present phonological/prosodic obstacles as well as grammatical challenges to these children. Consequently, non-word repetition emerges as a predictor of these grammatical weaknesses in SLI, unlike the profile observed in typically developing Italian children.

Deeper attentional masking by lateral objects in children with autism

Autism spectrum disorder (ASD) is often associated with a detail-oriented perception and overselective attention in visual tasks, such as visual search and crowding. These results were obtained manipulating exclusively the spatial properties of the stimuli: few is known about the spatio-temporal dynamics of visual processing in ASD. In this study we employed an attentional masking (AM) paradigm comparing children with ASD and IQ-matched typically developing (TD) controls. The AM effect refers to an impaired identification of a target followed by a competitive masking object at different proximities in space and time. We found that ASD and TD groups did not differ in the AM effect provoked by the competitive object displayed in the same position of the target. In contrast, children with ASD showed a deeper and prolonged interference than the TD group when the masking object was displayed in the lateral position. These psychophysical results suggest that the inefficient attentional selection in ASD depends on the spatio-temporal interaction between competitive visual objects. These evidence are discussed in the light of the ASD altered neural connectivity hypothesis and the reentrant theory of perception.