Anne-Lise Leclercq

Serial-Order Short-Term Memory Predicts Vocabulary Development: Evidence from a Longitudinal Study.

Serial-order short-term memory (STM), as opposed to item STM, has been shown to be very consistently associated with lexical learning abilities in cross-sectional study designs. This study investigated longitudinal predictions between serial-order STM and vocabulary development. Tasks maximizing the temporary retention of either serial-order or item information were administered to kindergarten children aged 4 and 5. At age 4, age 5, and from age 4 to age 5, serial-order STM capacities, but not item STM capacities, were specifically associated with vocabulary development. Moreover, the increase of serial-order STM capacity from age 4 to age 5 predicted the increase of vocabulary knowledge over the same time period. These results support a theoretical position that assumes an important role for serial-order STM capacities in vocabulary acquisition.

Neural networks for short-term memory for order differentiate high and low proficiency bilinguals

Short-term memory (STM) for order information, as compared to STM for item information, has been shown to be a critical determinant of language learning capacity. The present fMRI study asked whether the neural substrates of order STM can serve as markers for bilingual language achievement. Two groups of German-French bilinguals differing in second language proficiency were presented STM tasks probing serial order or item information. During order STM but not item STM tasks, the high proficiency group showed increased activation in the lateral orbito-frontal and the superior frontal gyri associated with updating and grouped rehearsal of serial order information. Functional connectivity analyses for order encoding showed a functional network involving the left IPS, the right IPS and the right superior cerebellum in the high proficiency group while the low proficiency group showed enhanced connectivity between the left IPS and bilateral superior temporal and temporo-parietal areas involved in item processing. The present data suggest that low proficiency bilinguals activate STM networks for order in a less efficient and differentiated way, and this may explain their poorer storage and learning capacity for verbal sequences.

Serial order short-term memory capacities and specific language impairment: No evidence for a causal association

This study re-explored the nature of verbal short-term memory (STM) deficits in children with specific language impairment (SLI), by distinguishing item and serial order STM processes. Recent studies have shown serial order STM capacity to be a critical determinant of language development, relative to item STM. In Experiment 1, 12 children with SLI, 12 age-matched children and 12 language-matched children were administered serial order recognition and reconstruction tasks. Experiment 2 assessed implicit serial learning abilities via a Hebb learning task. The SLI group showed impaired performance for the serial order reconstruction and recognition tasks, relative to language-matched and/or age-matched control groups. However, normal serial position effects were observed in all SLI children in the serial order reconstruction task, suggesting normal coding of serial position information. Similarly, performance on the Hebb serial learning task was at chronological age appropriate levels. Experiment 3 showed that the group differences observed for the serial order STM tasks in Experiment 1 disappeared when the SLI group was compared to a mental age-matched control group. Experiment 4 showed similar performance levels in the SLI group and the mental age-matched control group for a nonword recognition task assessing item STM capacities. This study shows that children with SLI have no specific impairments for serial order and item STM components but that poorer general cognitive efficiency is related to functional limitations in verbal STM tasks. The data are in line with limited information processing accounts of SLI.

The sentence repetition task: A powerful diagnostic tool for French children with specific language impairment

This study assesses the diagnostic accuracy and construct validity of a sentence repetition task that is commonly used for the identification of French children with specific language impairment (SLI). Thirty-four school-aged children with a confirmed, diagnostically based diagnosis of SLI, and 34 control children matched on age and nonverbal abilities performed the sentence repetition task. Two general scoring measures took into account the verbatim repetition of the sentence and the number of words accurately repeated. Moreover, five other scoring measures were applied to their answers in order to separately take into account their respect of lexical items, functional items, syntax, verb morphology, and the general meaning of the sentence. Results show good to high levels of sensitivity and specificity at the three cut-off points for all scoring measures. A principal component analysis revealed two factors. Scoring measures for the respect of functional words, syntax and verb morphology provided the largest loadings to the first factor, while scoring measures for the respect of lexical words and general semantics provided the largest loadings to the second factor. Sentence repetition appears to be a valuable tool to identify SLI in French children, and the ability to repeat sentences correctly is supported by two factors: a morphosyntactic factor and a lexical factor.

Nonword repetition problems in children with specific language impairment: A deficit in accessing long-term linguistic representations?

Children with specific language impairment (SLI) consistently show poor nonword repetition (NWR) performance. However, the reason for these difficulties remains a matter of intensive debate. Nonword repetition is a complex psycholinguistic task that heavily relies upon phonological segmentation and phonological knowledge, and even lexical knowledge. This study aims at investigating various linguistic factors that can be at the root of difficulties in children with Specific Language Impairment when repeating nonwords, with the goal of achieving a better understanding of the linguistic processes supporting nonword processing. Linguistic complexity was assessed by manipulating lexicality, syllabic complexity, and perceptual difficulty in NWR tasks. Fifteen children with Specific Language Impairment, 15 typically developing controls matched on both age and performance IQ, and 15 typically developing children matched on lexical knowledge participated in this study. Children with Specific Language Impairment performed overall more poorly than age- and IQ-matched children and lexical age–matched children. Importantly, children with Specific Language Impairment showed lower lexicality and syllabic complexity effects in their NWR performances. These results are compatible with difficulties to retrieve lexical and sublexical phonological knowledge in the context of NWR tasks.

The Impact of Visual Complexity on Visual Short-Term Memory in Children with Specific Language Impairment

Many studies have assessed visual short-term memory (VSTM) abilities in children with specific language impairment (SLI), with contrasting results: some studies observed preserved VSTM capacities, while others reported impaired VSTM. The present study explores the hypothesis that the complexity of the visual information to be encoded and stored might underlie these discrepancies. Four VSTM conditions were administered to a group of 15 children with SLI, as well as to two groups of typically developing children, matched for chronological age and for VSTM capacity for visually simple stimuli, respectively. The stimuli to be remembered varied in their visual similarity and in the number of their visual features. Across the four VSTM conditions, children with SLI showed significantly reduced performance relative to an age-matched control group, and they were more strongly affected by visual similarity and number of features when compared to a control group matched for VSTM capacity for visually simple stimuli. The present results support the hypothesis that stimulus complexity is a determining factor of the poor VSTM performances in children with SLI.

Beyond stuttering: Speech disfluencies in normally fluent French-speaking children at age 4

ABSTRACT The aim of this study was to establish normative data on the speech disfluencies of normally fluent French-speaking children at age 4, an age at which stuttering has begun in 95% of children who stutter (Yairi & Ambrose, 2013). Fifty monolingual French-speaking children who do not stutter participated in the study. Analyses of a conversational speech sample comprising 250–550 words revealed an average of 10% total disfluencies, 2% stuttering-like disfluencies and around 8% non-stuttered disfluencies. Possible explanations for these high speech disfluency frequencies are discussed, including explanations linked to French in particular. The results shed light on the importance of normative data specific to each language.

The Impact of Attentional Allocation Capacities on Nonword Repetition in Children with Specific Language Impairment

Abstract This study aimed at directly assessing the hypothesis that attentional allocation capacity influences poor nonword repetition (NWR) performances in children with specific language impairment (SLI), using an attention demanding visual search task given concurrently with the NWR task. Twenty-one children with SLI, 21 typically developing children matched on age and 21 typically developing children matched on nonword span performed an immediate serial recall task of nonwords. The nonword lists were presented either alone or concurrently with the visual search task. Overall, results revealed a resource-sharing trade-off between the two tasks. Children with SLI were affected to the same extent as their span-matched controls by the necessity to allocate their attentional resources between the two tasks. Interestingly, nonword processing strategies seemed to differ among groups: age-matched controls allocated a larger part of their attentional resources to the encoding stage, whereas nonword recall was more attention demanding in children with SLI and younger controls.

Complexity markers in morphosyntactic productions in French-speaking children with specific language impairment (SLI).

Abstract The usage-based theory considers that the morphosyntactic productions of children with SLI are particularly dependent on input frequency. When producing complex syntax, the language of these children is, therefore, predicted to have a lower variability and to contain fewer infrequent morphosyntactic markers than that of younger children matched on morphosyntactic abilities. Using a spontaneous language task, the current study compared the complexity of the morphological and structural productions of 20 children with SLI and 20 language-matched peers (matched on both morphosyntactic comprehension and mean length of utterance). As expected, results showed that although basic structures were produced in the same way in both groups, several complex forms (i.e. tenses such as Imperfect, Future or Conditional and Conjunctions) were less frequent in the productions of children with SLI. Finally, we attempted to highlight complex linguistic forms that could be good clinical markers for these children.