154 research outputs found
Number word use in toddlerhood is associated with number recall performance at seven years of age
No full textPrevious studies have shown that verbal working memory and vocabulary acquisition are linked in early childhood. However, it is unclear whether acquisition of a narrow range of words during toddlerhood may be particularly related to recall of the same words later in life. Here we asked whether vocabulary acquisition of number words, location and quantifier terms over the first three years of life are associated with verbal and visuospatial working memory at seven years. Our results demonstrate that children who produced more number words between 20-26 months and started to produce the number words 1-10 earlier showed greater number recall at 7 years of age. This link was specific to numbers and neither extended to quantifier and location terms nor verbal and visuospatial working memory performance with other stimuli. These findings suggest a category-specific link between the mental lexicon of number words and working memory for numbers at an early age. © 2014 Libertus et al
Automatic vocalisation-based detection of fragile X syndrome and Rett syndrome
No full textFragile X syndrome (FXS) and Rett syndrome (RTT) are developmental disorders currently not diagnosed before toddlerhood. Even though speech-language deficits are among the key symptoms of both conditions, little is known about infant vocalisation acoustics for an automatic earlier identification of affected individuals. To bridge this gap, we applied intelligent audio analysis methodology to a compact dataset of 4454 home-recorded vocalisations of 3 individuals with FXS and 3 individuals with RTT aged 6 to 11 months, as well as 6 age- and gender-matched typically developing controls (TD). On the basis of a standardised set of 88 acoustic features, we trained linear kernel support vector machines to evaluate the feasibility of automatic classification of (a) FXS vs TD, (b) RTT vs TD, (c) atypical development (FXS+RTT) vs TD, and (d) FXS vs RTT vs TD. In paradigms (a)–(c), all infants were correctly classified; in paradigm (d), 9 of 12 were so. Spectral/cepstral and energy-related features were most relevant for classification across all paradigms. Despite the small sample size, this study reveals new insights into early vocalisation characteristics in FXS and RTT, and provides technical underpinnings for a future earlier identification of affected individuals, enabling earlier intervention and family counselling
Highlighting the first 5 months of life: General movements in infants later diagnosed with autism spectrum disorder or Rett syndrome
No full textWe review literature identifying an association between motor abnormality in the first 5 months of infancy and later diagnosis of autism spectrum disorder (ASD) or Rett syndrome (RTT). The assessment of the quality of early spontaneous movements (also known as the assessment of general movements; GMs) is a diagnostic tool that has repeatedly proven to be valuable in detecting early markers for neurodevelopmental disorders. Even though the rate of occurrence of abnormal GMs is exceedingly high in infants later diagnosed with ASD, we endorse further studies using this method either based on family videos or its prospective implementation in high-risk sibling studies to evaluate the power of GM assessment as one potential marker for early maldevelopment in this cohort. © 2013 Elsevier Ltd
Identifying Atypical Development: A Role of Day-Care Workers?
No full textIdentifying the early signs of developmental disability is important for ensuring timely diagnosis and early intervention. Day-care workers may be in a prime position to notice potential developmental deviations, but it is unclear if they can accurately recognize subtle early signs of atypical development. Sixty day-care workers examined home-videos of very young children with fragile X syndrome and typically developing children. Results indicated that most day-care workers can distinguish typical and atypical development in general and might therefore have an important role in early identification. Special work experience and advanced pedagogical training appeared to boost day-care workers’ sensitivity to detect atypical features in early development and to provide effective daily surveillance. Scientific understanding and public awareness of young children at risk for developmental disorders have substantially increased in the past few decades. The growing number of studies on early human development have provided new empirical findings that have altered perspectives on the age-specific phenomena, pathways, and profiles associated with several developmental and genetic disorders (e.g., Johnson et al. 2015; Marschik et al. 2013; Messinger et al. 2013; Thomas et al. 2009). The advancements related to studies on late detected developmental disorders (LDDDs), for example, are particularly evident in research on autism spectrum disorder (ASD; e.g., Bölte et al. 2016, 2013; Bontinck et al. 2018; Bussu et al. 2018; Gliga et al. 2014; Messinger et al. 2013; Roeyers 2018). Research advances have also contributed to what appears to be greater acknowledgment of the significance of earlier detection of atypical development to enable timely intervention and support. In many European countries, as the number of working-mothers keeps climbing, the need of public childcare services increases steadily. In Austria, for example, the proportion of infants and children under 2 years of age who are attending day-care centres doubled from 2007 to 2017. In some urban areas, up to 45% of children aged 0 to 2-years attend day-care, of whom more than 90% spend 6–10 h per day with professional caregivers (Statistik Austria 2018). These day-care workers could thus be seen as among the most important care persons for many young children. As a consequence, it would seem important to investigate the potential role of day-care workers in the early detection of deviant development in young children. For example, might it be feasible to enlist day-care workers in the process of screening children for ASD? Such issues have been highlighted in a number of recent publications (Branson et al. 2008; Dereu et al. 2012; Janus et al. 2018; Janvier et al. 2016; Larsen et al. 2018a, b; Nordahl-Hansen et al. 2018, 2013). Indeed, results from some studies suggest that day-care workers have the competency to accurately report early signs of autism by applying well-designed behavioural checklists (Dereu et al. 2010; Larsen et al. 2018b). There might also be some potential advantages in integrating the help of day-care workers because such personnel often have training and knowledge of early child development and have considerable hands-on experience in working with children of comparable ages and diverse developmental profiles. Given that developmental disabilities affect at least 7 to 9% of young children (Olusanya et al. 2018; Zablotsky et al. 2017), it may be important to involve day-care workers as potential screeners of developmental disability. Unlike parents, day-care workers are likely to be more objective. The input from their daily surveillance may complement to our understanding of the prodromal period of LDDDs and potentially contribute to earlier identification, hence be of important public and scientific interest. Fragile X syndrome (FXS) is one of these LDDDs. Similar to several other disorders, such as Rett syndrome (RTT) and ASD, syndrome related behavioural and physical features are often subtle and elusive to detect at first, which of course makes early identification more challenging. Still, atypical early signs emerging in the first years of life across different developmental domains have been reported to be perceptible to parents of children with FXS (e.g., Hinton et al. 2013; Zhang et al. 2017). Some of these signs are frequently presented and often captured by home videos. With a benchmark procedure retrospectively analysing home videos of children with FXS, we, among other researchers, demonstrated that these signs can be readily identified and classified by professionals (Zhang et al. 2018; see also Baranek et al. 2005). Early phenotypes of FXS present a broad spectrum of atypical neurobehavioural features across various domains (e.g., motor, cognition, speech-language, social-communication), which are not specific to FXS (e.g., Haessler et al. 2016; Hagerman 2002; Kidd et al. 2014; Marschik et al. 2014; Raspa et al. 2017; Roche et al. 2018; Zhang et al. 2017). As early signs of FXS overlap with peculiarities of children with other developmental and genetic disorders, to identify these signs requires sensitivity to deviant development in general and not necessarily expertise in a specific syndrome. Pertinent to the current study, we intended to utilize home-video footage showing behaviours of different developmental areas of typically developing children and children with FXS as material to tap on day-care workers’ general awareness of early development. We adapted a video reviewing procedure used by Burford et al. (2003) by adding benchmark assessments of neurodevelopmental features. Specifically, we aimed to investigate whether day-care workers perceive young children with typical or atypical development differently. In Addition, we intended to find out whether they are able to accurately identify typical and atypical features in early development. As day-care workers have different training and experience backgrounds, we also aimed to answer whether these factors modify day-care workers’ perceptions of early developmental phenomena
En route to disentangle early behavioral abnormalities as early markers for maldevelopment: learning from Rett syndrome
No full textAddressing sequelae of developmental regression associated with developmental disabilities: A systematic review of behavioral and educational intervention studies
No full textDevelopmental regression is characteristic of Rett syndrome and it also occurs in a number of other develop. mental disabilities. To assist clinicians in identifying promising therapeutic approaches, we identified 38 studies that sought to improve adaptive behavior functioning in cases where developmental regression had either already occurred or was likely to occur. Studies were summarized in terms of (a) participants, (b) intervention, (c) dependent variables, (d) outcomes, (e) study design, and (f) certainty of evidence. The available literature in. eluded 136 participants from preschoolers to adults. Most participants (n = 132) had Rett syndrome. Interventions targeted a range of dependent variables (e.g., challenging behavior, communication, motor, and play skills). Multi-component interventions derived from behavior analytic principles were the norm, suggesting the need for clinical expertise in the application of such principles. However, only 12 studies (with 44 participants) were rated as providing conclusive evidence of a positive intervention effect. Future research on the mechanisms underlying developmental regression might lead to new and more effective interventions
Vocalisation repertoire at the end of the first year of life: an exploratory comparison of Rett syndrome and typical development
No full textRett syndrome (RTT) is a rare, late detected developmental disorder associated with severe deficits in the speech-language domain. Despite a few reports about atypicalities in the speech-language development of infants and toddlers with RTT, a detailed analysis of the pre-linguistic vocalisation repertoire of infants with RTT is yet missing. Based on home video recordings, we analysed the vocalisations between 9 and 11 months of age of three female infants with typical RTT and compared them to three age-matched typically developing (TD) female controls. The video material of the infants had a total duration of 424 min with 1655 infant vocalisations. For each month, we (1) calculated the infants’ canonical babbling ratios with CBRUTTER, i.e., the ratio of number of utterances containing canonical syllables to total number of utterances, and (2) classified their pre-linguistic vocalisations in three non-canonical and four canonical vocalisation subtypes. All infants achieved the milestone of canonical babbling at 9 months of age according to their canonical babbling ratios, i.e. CBRUTTER ≥ 0.15. We revealed overall lower CBRsUTTER and a lower proportion of canonical pre-linguistic vocalisations consisting of well-formed sounds that could serve as parts of target-language words for the RTT group compared to the TD group. Further studies with more data from individuals with RTT are needed to study the atypicalities in the pre-linguistic vocalisation repertoire which may portend the later deficits in spoken language that are characteristic features of RTT
Efficient collection and representation of preverbal data in typical and atypical development
No full textHuman preverbal development refers to the period of steadily increasing vocal capacities until the emergence of a child’s first meaningful words. Over the last decades, research has intensively focused on preverbal behavior in typical development. Preverbal vocal patterns have been phonetically classified and acoustically characterized. More recently, specific preverbal phenomena were discussed to play a role as early indicators of atypical development. Recent advancements in audio signal processing and machine learning have allowed for novel approaches in preverbal behavior analysis including automatic vocalization-based differentiation of typically and atypically developing individuals. In this paper, we give a methodological overview of current strategies for collecting and acoustically representing preverbal data for intelligent audio analysis paradigms. Efficiency in the context of data collection and data representation is discussed. Following current research trends, we set a special focus on challenges that arise when dealing with preverbal data of individuals with late detected developmental disorders, such as autism spectrum disorder or Rett syndrome
Dyslexie und ihre neuronale Signatur
No full textDyslexie, als eine der häufigsten umschriebenen Entwicklungsstörungen, ist eine schwerwiegende und persistierende Problematik schriftsprachlicher Verarbeitungsprozesse. Ursächlich für Dyslexie werden phonologische, auditive oder visuelle Defizite, Schwierigkeiten beim schnellen Benennen sowie Automatisierungsdefizite diskutiert. Aufgrund der familiären Häufung der Dyslexie gilt eine genetische Grundlage für diese Störung als gesichert. Post-mortem Untersuchungen fanden bei Dyslektikern Ektopien und Dysplasien im sprachassoziierten perisylvischen Cortex. Ob die Plana temporalia bei Dyslektikern im Vergleich zu Nicht-Dyslektikern symmetrisch sind, wird noch kontroversiell diskutiert. Neben neuroanatomischen Auffälligkeiten wurden mittels funktioneller bildgebender Verfahren auch neurofunktionelle Abweichungen bei Dyslektikern nachgewiesen: Teile der parieto-temporalen und okzipito-temporalen Strukturen der linken Hemisphäre sind bei spezifischen Aufgaben vermindert aktiviert, während linker und rechter Gyrus frontalis inferior und rechtshemisphärische okzipito-temporale Strukturen eine vermehrte Aktivierung aufweisen. Eye-Tracking Studien zeigten bei Dyslektikern häufig längere Fixationen, kleinere Sakkaden und mehr Regressionen als bei normal entwickelten Lesern. Noch immer sind neurofunktionelle und -strukturelle Ergebnisse inkonsistent, was unter anderem mit unterschiedlichen Messverfahren, Altersunterschieden der Probanden, geringer Sample-Größe, uneinheitlicher Definition der Dyslexie und der Heterogenität der Störung selbst zusammenhängt.Dyslexia is one of the most common specific developmental disorders. Dyslexics exhibit a profound and persistent reading disorder, frequently accompanied by spelling difficulties. Current theories assume dyslexia to be caused by phonological, auditory or visual deficits, or by deficits in rapid naming and automatisation. Due to the familial risk of this developmental disorder, a genetic origin is being discussed as well. Post-mortem studies revealed ectopias and dysplasias in the language-associated perisylvian cortex of dyslexics. Whether the plana temporalia are symmetrically distributed or asymmetric as in non-dyslexics is still the subject of controversial discussion. In neurofunctional studies dyslexics showed underactivated left-hemispheric parieto-temporal and occipito-temporal structures. However, there was an overactivation of the left and right inferior frontal gyri and of the right-hemispheric occipito-temporal structures. Various eye-tracking studies revealed longer fixations, shorter saccades and more frequent regressions in dyslexics than in normal readers. Neuroanatomic and neurophysiological results are still inconsistent, which is certainly due to the diversity of methodological approaches, to age differences between the participants, small sample sizes, heterogeneous definitions of dyslexia, and to the phenotypic heterogeneity of the disorder itself
Monozygotic Twins with Rett Syndrome: Phenotyping the First Two Years of Life
No full textThe first 2 years of life for children with Rett syndrome (RTT) have previously been viewed as relatively asymptomatic. However, it is possible that subtle symptoms may be present in early development. To identify possible early indicators of RTT, we analysed videotapes of two twin girls with RTT. The videotapes were analysed to (a) describe the motor and communicative development of this twin pair with RTT; and to (b) explore whether early abnormalities and their age of onset differed between the twins and were related to their later clinical phenotypes. The results indicated several neurodevelopmental abnormalities present before the children exhibited any obvious signs of regression. Abnormalities were evident in the motor, speech-language and communicative domains. These data support an emerging evidence base showing the presence of developmental abnormalities in children with RTT during the first year of life. The results have implications for early screening and clinical assessment
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