Research Review: Emanuel Miller Memorial Lecture 2012 - neuroscientific studies of intervention for language impairment in children: interpretive and methodological problems

Mindfulness related changes in grey matter: a systematic review and meta-analysis

Knowing target regions undergoing strfuncti changes caused by behavioural interventions is paramount in evaluating the effectiveness of such practices. Here, using a systematic review approach, we identified 25 peer-reviewed magnetic resonance imaging (MRI) studies demonstrating grey matter changes related to mindfulness meditation. An activation likelihood estimation (ALE) analysis (n = 16) revealed the right anterior ventral insula as the only significant region with consistent effect across studies, whilst an additional functional connectivity analysis indicates that both left and right insulae, and the anterior cingulate gyrus with adjacent paracingulate gyri should also be considered in future studies. Statistical meta-analyses suggest medium to strong effect sizes from Cohen’s d ~ 0.8 in the right insula to ~ 1 using maxima across the whole brain. The systematic review revealed design issues with selection, information, attrition and confirmation biases, in addition to weak statistical power. In conclusion, our analyses show that mindfulness meditation practice does induce grey matter changes but also that improvements in methodology are needed to establish mindfulness as a therapeutic intervention.

Annual Research Review: Educational neuroscience: progress and prospects

Educational neuroscience is an interdisciplinary research field that seeks to translate research findings on neural mechanisms of learning to educational practice and policy and to understand the effects of education on the brain. Neuroscience and education can interact directly, by virtue of considering the brain as a biological organ that needs to be in the optimal condition to learn ('brain health'); or indirectly, as neuroscience shapes psychological theory and psychology influences education. In this article, we trace the origins of educational neuroscience, its main areas of research activity and the principal challenges it faces as a translational field. We consider how a pure psychology approach that ignores neuroscience is at risk of being misleading for educators. We address the major criticisms of the field comprising, respectively, a priori arguments against the relevance of neuroscience to education, reservations with the current practical operation of the field, and doubts about the viability of neuroscience methods for diagnosing disorders or predicting individual differences. We consider future prospects of the field and ethical issues it raises. Finally, we discuss the challenge of responding to the (welcome) desire of education policymakers to include neuroscience evidence in their policymaking, while ensuring recommendations do not exceed the limitations of current basic science.

A Translational Framework of Educational Neuroscience in Learning Disorders

Neuroimaging has undergone enormous progress during the last two and a half decades. The combination of neuroscientific methods and educational practice has become a focus of interdisciplinary research in order to answer more applied questions. In this realm, conditions that hamper learning success and have deleterious effects in the population - such as learning disorders (LD) - could especially profit from neuroimaging findings. At the moment, however, there is an ongoing debate about how far neuroscientific research can go to inform the practical work in educational settings. Here, we put forward a theoretical translational framework as a method of conducting neuroimaging and bridging it to education, with a main focus on dyscalculia and dyslexia. Our work seeks to represent a theoretical but mainly empirical guide on the benefits of neuroimaging, which can help people working with different aspects of LD, who need to act collaboratively to reach the full potential of neuroimaging. We provide possible ideas regarding how neuroimaging can inform LD at different levels within our multidirectional framework, i.e., mechanisms, diagnosis/prognosis, training/intervention, and community/education. In addition, we discuss methodological, conceptual, and structural limitations that need to be addressed by future research.

Direct object pronoun sentence processing in Spanish-English children with/without Specific Language Impairment and adults: A cross-modal priming study

PURPOSE

This paper examines whether bilingual children with Specific Language Impairment (SLI) showed limited comprehension of Direct Object (DO) pronoun sentences and/or morphosyntactic priming compared to children with Typical Language Development (TLD) and adults. We analyzed the relation of these morphosyntactic processes to other psycholinguistic abilities, according to the MUC (Memory-Unification-Control) model.

METHOD

Ten bilingual native Spanish-speaking children with SLI (8;3-10;6) and 10 age-matched children with TLD (7;6-10;10) received a psycholinguistic evaluation in Spanish-English. The 20 children and 10 adults (19-34) performed an on-line cross-modal pronoun task. They listened to long distance animate DO pronoun sentences, and filler sentences without any pronoun. At the offset of the pronoun in each pronoun sentence, a picture of an animal for the antecedent (match condition), another animal for the second noun (mismatch), or an unrelated object (neutral) was displayed on the screen. In the filler sentences, a picture of an object that depicted the first noun, appeared at the offset of another later noun. Participants decided whether that pictured item was "alive"/"not alive" by pressing two keys on the computer keyboard. Immediately after, they answered an oral comprehension question about the DO pronoun sentence.

RESULTS

Bilingual children with SLI showed significantly poorer comprehension of DO pronoun sentences than bilingual children with TLD. Pronoun sentence understanding in the overall children correlated significantly with oral sentence completion, expressive vocabulary abilities, auditory story comprehension, and the non-word repetition task, all in Spanish. Adults showed significantly the highest pronoun sentence comprehension, and the fastest animacy decisions across conditions; it was the only group showing a significant behavioral morphosyntactic priming effect. All groups exhibited high accuracy in the animacy decisions across conditions, although children with SLI showed lower accuracy and more variability.

CONCLUSION

Bilingual Spanish-English children with SLI showed significant limitations in understanding long distance animate DO pronoun sentences. The deficits were also related to weak morphosyntactic, lexical, and/or phonological representations stored in their memory. These processes may be harder to combine in the unification process, and also to control for answering the comprehension questions. Clinical and educational implications are discussed.

The effect of coloured overlays and lenses on reading: a systematic review of the literature

PURPOSE

There are many anecdotal claims and research reports that coloured lenses and overlays improve reading performance. Here we present the results of a systematic review of this literature and examine the quality of the evidence.

METHODS

We systematically reviewed the literature concerning the effect of coloured lenses or overlays on reading performance by searching the PsychInfo, Medline and Embase databases. This revealed 51 published items (containing 54 data sets). Given that different systems are in use for issuing coloured overlays or lenses, we reviewed the evidence under four separate system headings (Intuitive, Irlen, Harris/Chromagen and Other), classifying each published item using the Cochrane Risk of Bias tool.

RESULTS

Although the different colour systems have been subjected to different amounts of scientific scrutiny, the results do not differ according to the system type, or whether the sample under investigation was classified as having visual stress (or a similarly defined condition), reading difficulty, or both. The majority of studies are subject to 'high' or 'uncertain' risk of bias in one or more key aspects of study design or outcome, with studies at lower risk from bias providing less support for the benefit of coloured lenses/overlays on reading ability. While many studies report improvements with coloured lenses, the effect size is generally small and/or similar to the improvement found with a placebo condition. We discuss the strengths and shortcomings of the published literature and, whilst acknowledging the difficulties associated with conducting trials of this type, offer some suggestions about how future trials might be conducted.

CONCLUSIONS

Consistent with previous reviews and advice from several professional bodies, we conclude that the use of coloured lenses or overlays to ameliorate reading difficulties cannot be endorsed and that any benefits reported by individuals in clinical settings are likely to be the result of placebo, practice or Hawthorne effects.

The Origins of Cognitive Deficits in Victimized Children: Implications for Neuroscientists and Clinicians

OBJECTIVE

Individuals reporting a history of childhood violence victimization have impaired brain function. However, the clinical significance, reproducibility, and causality of these findings are disputed. The authors used data from two large cohort studies to address these research questions directly.

METHOD

The authors tested the association between prospectively collected measures of childhood violence victimization and cognitive functions in childhood, adolescence, and adulthood among 2,232 members of the U.K. E-Risk Study and 1,037 members of the New Zealand Dunedin Study who were followed up from birth until ages 18 and 38 years, respectively. Multiple measures of victimization and cognition were used, and comparisons were made of cognitive scores for twins discordant for victimization.

RESULTS

Individuals exposed to childhood victimization had pervasive impairments in clinically relevant cognitive functions, including general intelligence, executive function, processing speed, memory, perceptual reasoning, and verbal comprehension in adolescence and adulthood. However, the observed cognitive deficits in victimized individuals were largely explained by cognitive deficits that predated childhood victimization and by confounding genetic and environmental risks.

CONCLUSIONS

Findings from two population-representative birth cohorts totaling more than 3,000 individuals and born 20 years and 20,000 km apart suggest that the association between childhood violence victimization and later cognition is largely noncausal, in contrast to conventional interpretations. These findings support the adoption of a more circumspect approach to causal inference in the neuroscience of stress. Clinically, cognitive deficits should be conceptualized as individual risk factors for victimization as well as potential complicating features during treatment.

On-line processing and comprehension of direct object pronoun sentences in Spanish-speaking children with Specific Language Impairment

Eleven native Spanish-speaking children with Specific Language Impairment (SLI) (8;3-10;11) and 11 typically developing children (8;7-10;8) received a comprehensive psycholinguistic evaluation. Participants listened to either Direct Object (DO) pronoun sentences or filler sentences without any pronoun, and they decided whether a picture on the screen (depicting the antecedent, another noun in the sentence, or an unrelated object) was 'alive'. They answered comprehension questions about pronoun sentences. Children with SLI showed significantly poorer comprehension of DO pronoun sentences when answering comprehension questions than children with Typical Language Development (TLD). This poor pronoun sentence understanding correlated significantly with poor auditory sentence completion, non-word repetition task and expressive vocabulary skills. Children with SLI were significantly slower in the animacy decisions than children with TLD across all pronoun and filler sentence conditions. Both groups exhibited high accuracy in the animacy decisions for any conditions. Clinical implications are discussed.

The Effect of Short-Term Auditory Training on Speech in Noise Perception and Cortical Auditory Evoked Potentials in Adults with Cochlear Implants

This study investigated whether a short intensive psychophysical auditory training program is associated with speech perception benefits and changes in cortical auditory evoked potentials (CAEPs) in adult cochlear implant (CI) users. Ten adult implant recipients trained approximately 7 hours on psychophysical tasks (Gap-in-Noise Detection, Frequency Discrimination, Spectral Rippled Noise [SRN], Iterated Rippled Noise, Temporal Modulation). Speech performance was assessed before and after training using Lexical Neighborhood Test (LNT) words in quiet and in eight-speaker babble. CAEPs evoked by a natural speech stimulus /baba/ with varying syllable stress were assessed pre- and post-training, in quiet and in noise. SRN psychophysical thresholds showed a significant improvement (78% on average) over the training period, but performance on other psychophysical tasks did not change. LNT scores in noise improved significantly post-training by 11% on average compared with three pretraining baseline measures. N1P2 amplitude changed post-training for /baba/ in quiet (p = 0.005, visit 3 pretraining versus visit 4 post-training). CAEP changes did not correlate with behavioral measures. CI recipients' clinical records indicated a plateau in speech perception performance prior to participation in the study. A short period of intensive psychophysical training produced small but significant gains in speech perception in noise and spectral discrimination ability. There remain questions about the most appropriate type of training and the duration or dosage of training that provides the most robust outcomes for adults with CIs.

Editorial: Neuroimaging in clinical psychiatry--when will the pay off begin?

For my father's generation, technology and progress are near synonyms. And his face still drops in disappointment when I tell him that we have found no imaging technique to improve the diagnosis, monitoring or treatment of psychiatric illness. His standard comment is: if the neurologists can, why can't you psychiatrists? Why indeed?

Music Training Increases Phonological Awareness and Reading Skills in Developmental Dyslexia: A Randomized Control Trial

There is some evidence for a role of music training in boosting phonological awareness, word segmentation, working memory, as well as reading abilities in children with typical development. Poor performance in tasks requiring temporal processing, rhythm perception and sensorimotor synchronization seems to be a crucial factor underlying dyslexia in children. Interestingly, children with dyslexia show deficits in temporal processing, both in language and in music. Within this framework, we test the hypothesis that music training, by improving temporal processing and rhythm abilities, improves phonological awareness and reading skills in children with dyslexia. The study is a prospective, multicenter, open randomized controlled trial, consisting of test, rehabilitation and re-test (ID NCT02316873). After rehabilitation, the music group (N = 24) performed better than the control group (N = 22) in tasks assessing rhythmic abilities, phonological awareness and reading skills. This is the first randomized control trial testing the effect of music training in enhancing phonological and reading abilities in children with dyslexia. The findings show that music training can modify reading and phonological abilities even when these skills are severely impaired. Through the enhancement of temporal processing and rhythmic skills, music might become an important tool in both remediation and early intervention programs.

Neuroscience illuminating the influence of auditory or phonological intervention on language-related deficits

Remediation programs for language-related learning deficits are urgently needed to enable equal opportunities in education. To meet this need, different training and intervention programs have been developed. Here we review, from an educational perspective, studies that have explored the neural basis of behavioral changes induced by auditory or phonological training in dyslexia, specific language impairment (SLI), and language-learning impairment (LLI). Training has been shown to induce plastic changes in deficient neural networks. In dyslexia, these include, most consistently, increased or normalized activation of previously hypoactive inferior frontal and occipito-temporal areas. In SLI and LLI, studies have shown the strengthening of previously weak auditory brain responses as a result of training. The combination of behavioral and brain measures of remedial gains has potential to increase the understanding of the causes of language-related deficits, which may help to target remedial interventions more accurately to the core problem.

Editorial: the power of treatment studies to explore causal processes in childhood disorders

We all have a tendency to be easily seduced by Occam's razor, or the desire to accept the simplest hypothesis to explain a given phenomenon. If we observe that children with ADHD come from more impoverished backgrounds or have diets that contain more additives than their peers, then a parsimonious theory would be that poverty and/or diet are causal factors in the development of ADHD. Such theories are all the more attractive because they suggest potential targets for intervention: improve family circumstances and child diet and symptoms of ADHD should diminish. Of course in reality untangling causal relationships is much more complicated. We now accept that many common disorders reflect the confluence of genetic and environmental risk factors, but that any given risk factor is likely to account for only a tiny amount of explained variance in symptom profile. What's more, in order to fulfil the promise of intervention, we must begin to unravel the precise mechanisms by which identified risk factors affect the developing system. This issue showcases two key methodologies for understanding causal influences on developmental disorders: longitudinal designs and well-controlled intervention studies. Both may employ statistical techniques that can identify the mediators of observed associations, elucidating potential mechanistic processes.

Developmental pathways to autism: a review of prospective studies of infants at risk

Autism Spectrum Disorders (ASDs) are neurodevelopmental disorders characterized by impairments in social interaction and communication, and the presence of restrictive and repetitive behaviors. Symptoms of ASD likely emerge from a complex interaction between pre-existing neurodevelopmental vulnerabilities and the child's environment, modified by compensatory skills and protective factors. Prospective studies of infants at high familial risk for ASD (who have an older sibling with a diagnosis) are beginning to characterize these developmental pathways to the emergence of clinical symptoms. Here, we review the range of behavioral and neurocognitive markers for later ASD that have been identified in high-risk infants in the first years of life. We discuss theoretical implications of emerging patterns, and identify key directions for future work, including potential resolutions to several methodological challenges for the field. Mapping how ASD unfolds from birth is critical to our understanding of the developmental mechanisms underlying this disorder. A more nuanced understanding of developmental pathways to ASD will help us not only to identify children who need early intervention, but also to improve the range of interventions available to them.

Cognitive development: gaming your way out of dyslexia?

A recent study found that dyslexic children trained on action video games show significant improvements on basic measures of both attention and reading ability, suggesting future directions for the study of dyslexia intervention paradigms.