Linking memory and language : Evidence for a serial-order learning impairment in dyslexia

The present study investigated long-term serial-order learning impairments, operationalized as reduced Hebb repetition learning (HRL), in people with dyslexia. In a first multi-session experiment, we investigated both the persistence of a serial-order learning impairment as well as the long-term retention of serial-order representations, both in a group of Dutch-speaking adults with developmental dyslexia and in a matched control group. In a second experiment, we relied on the assumption that HRL mimics naturalistic word-form acquisition and we investigated the lexicalization of novel word-forms acquired through HRL. First, our results demonstrate that adults with dyslexia are fundamentally impaired in the long-term acquisition of serial-order information. Second, dyslexic and control participants show comparable retention of the long-term serial-order representations in memory over a period of one month. Third, the data suggest weaker lexicalization of newly acquired word-forms in the dyslexic group. We discuss the integration of these findings into current theoretical views of dyslexia.Peer reviewedFinal Accepted Versio

Is implicit motor learning preserved after stroke? A systematic review with meta-analysis

© 2016 Kal et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Many stroke patients experience difficulty with performing dual-tasks. A promising intervention to target this issue is implicit motor learning, as it should enhance patients' automaticity of movement. Yet, although it is often thought that implicit motor learning is preserved poststroke, evidence for this claim has not been systematically analysed yet. Therefore, we systematically reviewed whether implicit motor learning is preserved post-stroke, and whether patients benefit more from implicit than from explicit motor learning. We comprehensively searched conventional (MEDLINE, Cochrane, Embase, PEDro, PsycINFO) and grey literature databases (BIOSIS, Web of Science, OpenGrey, British Library, trial registries) for relevant reports. Two independent reviewers screened reports, extracted data, and performed a risk of bias assessment. Overall, we included 20 out of the 2177 identified reports that allow for a succinct evaluation of implicit motor learning. Of these, only 1 study investigated learning on a relatively complex, whole-body (balance board) task. All 19 other studies concerned variants of the serial-reaction time paradigm, with most of these focusing on learning with the unaffected hand (N = 13) rather than the affected hand or both hands (both: N = 4). Four of the 20 studies compared explicit and implicit motor learning post-stroke. Meta-analyses suggest that patients with stroke can learn implicitly with their unaffected side (mean difference (MD) = 69 ms, 95% CI[45.1, 92.9], p < .00001), but not with their affected side (standardized MD = -.11, 95% CI[-.45, .25], p = .56). Finally, implicit motor learning seemed equally effective as explicit motor learning post-stroke (SMD = -.54, 95% CI[-1.37, .29], p = .20). However, overall, the high risk of bias, small samples, and limited clinical relevance of most studies make it impossible to draw reliable conclusions regarding the effect of implicit motor learning strategies post-stroke. High quality studies with larger samples are warranted to test implicit motor learning in clinically relevant contexts

Behavioural and educational outcomes following extremely preterm birth : current controversies and future directions

As a consequence of improved survival rates for extremely preterm (EP; <28 weeks of gestation) births, there is a growing body of evidence detailing the impact of extreme prematurity on outcomes throughout childhood and adolescence. Historically, attention first focused on documenting rates of sensory impairments and severe neurodevelopmental disabilities. However, over recent years, there has been growing interest in the impact of EP birth on long term mental health and educational outcomes. In this chapter we review literature relating to the impact of EP birth on attention, social and emotional problems, psychiatric disorders and educational outcomes. We also outline current controversies in the field. In particular, we present emergent research exploring developmental trajectories to determine whether the sequelae associated with EP birth represent a developmental delay or persistent deficit, and we consider what approaches to intervention may be most fruitful in improving behavioural and educational outcomes in this population

Research Review: Language and specific learning disorders in children and their co-occurrence with internalizing and externalizing problems: a systematic review and meta-analysis

Background: Some studies suggest that children with language and learning disorders (LLDs) show more internalizing and externalizing problems than their peers. However, the available evidence remains inconsistent, especially regarding the conditions under which these psychological problems occur. Methods: We performed a meta-analysis of studies comparing children with LLDs and controls on internalizing (53 independent samples, 135 effect sizes) and externalizing problems (37 independent samples, 61 effect sizes) separately. Results: Children with LLDs showed higher internalizing (Hedges\u2019 g = 0.36) and externalizing problems (Hedges\u2019 g = 0.42) than controls did. The group standardized difference in internalizing problems was moderated by the primary disorder, with children with language disorders showing more internalizing problems than those with reading disorders. The severity of the primary disorder, IQ, and age did not moderate Hedge\u2019s g between children with LLDs and controls in internalizing and externalizing outcomes. The same pattern was found for gender as a moderator of Hedge\u2019s g in internalizing problems, while findings for externalizing problems were inconclusive. The results were consistent when methodological variables were assessed, also for informant, sample size, and geographical area. Clinical samples with LLDs reported higher internalizing problems respect to those with difficulties, but findings on externalizing outcomes were limited. Similarly, results on the presence of additional symptoms in learning and language, self-concept, and socioeconomic status were inconclusive, as few studies reported this information. Results were robust when publication bias, publication year, and study quality were assessed. Conclusions: There is evidence that children with LLDs report higher internalizing and externalizing problems than controls do. Children with language disorders seemed more vulnerable to report more internalizing problems, and clinical samples reported higher problems than those with difficulties. For clinical practice, assessment and interventions should target socioemotional skills to support the psychological well-being of children with LLDs

Long-term prognosis of low language proficiency in children

OBJECTIVES: This is a protocol for a Cochrane Review (prognosis). The objectives are as follows:. Primary objectives (Table presented.) The main objective of this review is to assess the long-term prognosis of an early language disorder or low language proficiency (LLP) for children aged four to eight years at baseline, and from age 12 years and up at follow-up, in areas of language and literacy, and broad quality of life outcomes in physical, psychological, independence, social relationships, and environment outcomes. This will include measures of mental and physical health, academic outcome, employment status, financial resources, and societal participation. We will ask the following research questions: 1) To what extent do children with LLP age four to eight years show higher risk for persistent difficulties with language and literacy into adolescence and adulthood? 2) To what extent do children age four to eight years, with LLP, experience higher risk for poor quality of life across five domains of physical, psychological, independence, social relationships, and environment well-being in adolescence, and adulthood (WHO 2012)?. Secondary objectives Secondary objectives are: 1) to understand how severity of early language problems affects long-term prognosis and quality of life, and 2) to identify gaps in the extant research. For instance, while the indicative sample of papers consistently report academic and employment outcomes, there is little evidence regarding physical or medical health outcomes. Investigation of sources of heterogeneity between studies We expect that there will be substantial heterogeneity between the included studies on the following variables: Diagnostic criteria Severity of language impairment Method of ascertainment (population study versus recruitment from special schools or clinics) Year of publication Age of outcome measurement Inclusiveness of non-verbal IQ (Specific Language Impairment versus Developmental Language Disorder) Stability of schooling (e.g. special school consistently versus changing between special school and mainstream classrooms) Literacy skills