Reproducibility of Brain Responses: High for Speech Perception, Low for Reading Difficulties

Neuroscience findings have recently received critique on the lack of replications. To examine the reproducibility of brain indices of speech sound discrimination and their role in dyslexia, a specific reading difficulty, brain event-related potentials using EEG were measured using the same cross-linguistic passive oddball paradigm in about 200 dyslexics and 200 typically reading 8-12-year-old children from four countries with different native languages. Brain responses indexing speech and non-speech sound discrimination were extremely reproducible, supporting the validity and reliability of cognitive neuroscience methods. Significant differences between typical and dyslexic readers were found when examined separately in different country and language samples. However, reading group differences occurred at different time windows and for different stimulus types between the four countries. This finding draws attention to the limited generalizability of atypical brain response findings in children with dyslexia across language environments and raises questions about a common neurobiological factor for dyslexia. Our results thus show the robustness of neuroscience methods in general while highlighting the need for multi-sample studies in the brain research of language disorders

Contralateral delay activity as a marker of visual working memory capacity: a multi-site registered replication

Visual working memory (VWM) is a temporary storage system capable of retaining information that can be accessed and manipulated by higher cognitive processes, thereby facilitating a wide range of cognitive functions. Electroencephalography (EEG) is used to understand the neural correlates of VWM with high temporal precision, and one commonly used EEG measure is an event-related potential called the contralateral delay activity (CDA). In a landmark study by Vogel and Machizawa (2004), the authors found that the CDA amplitude increases with the number of items stored in VWM and plateaus around three to four items, which is thought to represent the typical adult working memory capacity. Critically, this study also showed that the increase in CDA amplitude between two-item and four-item arrays correlated with individual subjects’ VWM performance. Although these results have been supported by subsequent studies, a recent study suggested that the number of subjects used in experiments investigating the CDA may not be sufficient to detect differences in set size and to provide a reliable account of the relationship between behaviorally measured VWM capacity and the CDA amplitude. To address this, the current study, as part of the #EEGManyLabs project, aims to conduct a multi-site replication of Vogel and Machizawa's (2004) seminal study on a large sample of participants, with a pre-registered analysis plan. Through this, our goal is to contribute to deepening our understanding of the neural correlates of visual working memory

The Effects of Type 1 Diabetes and its Long-Term Complications on Physical and Mental Health Status

Objective: To analyse how type 1 diabetes mellitus (DM) and the symptoms of its chronic long-term complications correlate with health status domains in the adult population in Finland. Methods: A representative sample of patients with type 1 DM was selected randomly from the Finnish drug reimbursement registry. Participants reported symptoms, diagnoses and treatments indicating the presence and time of appearance of long-term complications, and completed the RAND 36 questionnaire. A principal component analysis was performed to compress the eight RAND 36 dimensions into composite domains of health status. The results were validated with split-sample analysis. Regression analyses were used to estimate the effects of age, sex, symptoms of long-term complications and comorbidities on the component T-scores. Results: Of the 752 (70.8%) responders, 592 fulfilled the criteria of type 1 DM. Of these, 82.6% fully completed the RAND 36 questionnaire. Principal component analysis of our data supports the theory of the 2-factor model of health, as physical and mental health domains were reflected unambiguously by different RAND 36 dimensions. The regression results show that the symptoms of long-term complications correlate more strongly with the physical than the mental domain of health status. Conclusion: Type 1 DM, and especially the symptoms of its long-term complications, correlate mainly with the physical domain of health, although the mental domain is also affected. The prevalence of long-term complications with type 1 DM is sufficiently high within the Finnish population to substantially influence the health status of people with type 1 DM.Quality-of-life, Type-1-diabetes-mellitus

Common Variant Burden Contributes to the Familial Aggregation of Migraine in 1,589 Families

Complex traits, including migraine, often aggregate in families, but the underlying genetic architecture behind this is not well understood. The aggregation could be explained by rare, penetrant variants that segregate according to Mendelian inheritance or by the sufficient polygenic accumulation of common variants, each with an individually small effect, or a combination of the two hypotheses. In 8,319 individuals across 1,589 migraine families, we calculated migraine polygenic risk scores (PRS) and found a significantly significantly higher common variant burden in familial cases (n = 5,317, OR = 1.76, 95% CI = 1.71-1.81, p = 1.7 x 10(-109)) compared to population cases from the FINRISK cohort (n = 1,101, OR = 1.32, 95% CI = 1.25-1.38, p = 7.2 x 10(-17)). The PRS explained 1.6% of the phenotypic variance in the population cases and 3.5% in the familial cases (including 2.9% for migraine without aura, 5.5% for migraine with typical aura, and 8.2% for hemiplegic migraine). The results demonstrate a significant contribution of common polygenic variation to the familial aggregation of migraine

The role of textured material in supporting perceptual-motor functions

Simple deformation of the skin surface with textured materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of textured materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD = 0.28, 95%CI = 0.46–0.09, Z = 2.99, P = 0.001; Tau2 = 0.02; Chi2 = 9.87, df = 6, P = 0.13; I2 = 39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2 = 0.13; Chi2 = 130.71, df = 26, P<0.0001; I2 = 85.98%, pooled samples in upright balance tasks: Tau2 = 0.09; Chi2 = 101.57, df = 13, P<0.001; I2 = 72.67%, and in elderly in upright balance tasks: Tau2 = 0.16; Chi2 = 39.42, df = 5, P<0.001; I2 = 83.05%. No effect was shown for walking tasks: Tau2 = 0.00; Chi2 = 3.45, df = 4, P = 0.27, I2 = 22.99%. Data provides unequivocal support for utilizing textured materials in young healthy populations for improving perceptual-motor performance. Future research is needed in young healthy populations under conditions where visual and proprioceptive information is challenged, as in high-speed movements, or where use of equipment mediates the performer-environment interaction or where dysfunctional information sources ‘compete’ for attention. In elderly and ailing populations data suggests further research is required to better understand contexts where texture can facilitate improved perceptual-motor performance