Search

Purpose: This study examined procedural and declarative learning and consolidation abilities in adults with developmental language disorder (DLD) relative to their typical language (TD) peers. Method: A total of 100 young adults (age 18-24 years) with (n = 21) and without (n = 79) DLD participated across two sites. Performance measures on a recognition memory task and a serial reaction time task were used to assess declarative and procedural memory, respectively. Performance was measured shortly after learning (8 a.m.) and again after a 12-hr, overnight delay (8 a.m.). Results: Linear mixed-effects modeling was used to examine the effects of time and group membership on task performance. For the serial reaction time task, there were significant effects of group (TD > DLD) and time (Day 1 > Day 2), but no interaction between them. For the recognition memory task, there was a significant interaction between group and time, driven by overnight gains in the TD group, combined with stable performance across days by those with DLD. Conclusions: In procedural memory, adults with DLD demonstrate a learning deficit relative to adults without DLD, but appear to have comparable retention of learned information. In declarative memory, adults with DLD demonstrate a deficit in the overnight enhancement of memory retrieval, despite typical-like learning exhibited when tested shortly after encoding.

Background: Fracture healing complications remain a major problem in trauma monitoring. An open wedge osteotomy of the distal radius provides a unique way of evaluating fracture healing. Since the introduction of cone-beam computed tomography (CBCT) at our institution, it has become the method of choice for assessing hand and wrist bones. To date, CT volumetry has been validated for multidetector CT (MDCT) but not for CBCT. Purpose: To assess osteotomy healing using CBCT volumetry and to evaluate two different segmentation techniques. Material and Methods: A total of 36 patients were surgically treated for malunited distal radius fractures with open-wedge osteotomy either leaving the void empty (open wedge empty [OWE]) or filled with bone graft substitutes (BGS). They were scanned using CBCT and MDCT postoperatively and after 3, 6, and 12 months. Segmentation was performed both manually and semi-automatically for volumetric measurement. Inter- and intra-observer reliability were assessed using intraclass correlation (ICC). Results: The median osteotomy volume in the OWE group postoperatively was 0.87 cm3 (range=0.42–2.72). At 3 months, all but one of the OWE volumes had diminished to half or less of their initial volume. In the BGS group, the median postoperative volume was 1.30 cm3 (range=0.73–1.81) and at 12 months, 76% of the initial volume remained. Reliability between CBCT and MDCT volumetry expressed as ICC was ≥0.96. ICC for the two segmentation techniques was ≥0.99 and ICC for inter-observer reliability ≥0.97. Conclusion: CBCT volumetry is a reliable tool and comparable to MDCT to quantify bone healing of an osteotomy. [ABSTRACT FROM AUTHOR]

Prior research has demonstrated that linguistic skills and knowledge contribute to successful reading acquisition. In contrast, little is known about the influence of domain-general learning abilities on reading. To investigate associations between general memory functions and reading during the early stages of learning to read, performance measures of word-level reading and of declarative and procedural learning were obtained in a cohort of 140 children, annually during their first 4 years of school. We hypothesized that differences in learning task performance would relate to reading ability in the early years, when children are first learning to read. We employed a series of linear mixed effects models to test the relationships between learning abilities and reading across time. Declarative learning performance predicted reading ability in first grade, while procedural learning performance predicted reading ability in second grade. Our findings suggest that reading acquisition may depend in part on general capacities for learning.

Substantial progress has been made in understanding the neurocognitive underpinnings of learning math. Building on this work, it has been hypothesized that declarative and procedural memory, two domain-general learning and memory systems, play important roles in acquiring math skills. In a longitudinal study, we tested whether in fact declarative and procedural memory predict children's math skills during elementary school years. A sample of 109 children was tested across grades 2, 3 and 4. Linear mixed-effects regression and structural equation modeling revealed the following. First, learning in declarative but not procedural memory was associated with math skills within each grade. Second, declarative but not procedural memory in each grade was related to math skills in all later grades (e.g., declarative memory in grade 2 was related to math skills in grade 4). Sensitivity analyses showed that the pattern of results was robust, except for the longitudinal prediction of later math skills when accounting for stable inter-individual differences via the inclusion of random intercepts. Our findings highlight the foundational role of early domain-general learning and memory in children's acquisition of math. [ABSTRACT FROM AUTHOR]

The declarative/procedural (DP) model posits that the learning, storage, and use of language critically depend on two learning and memory systems in the brain: declarative memory and procedural memory. Thus, on the basis of independent research on the memory systems, the model can generate specific and often novel predictions for language. Till now most such predictions and ensuing empirical work have been motivated by research on the neurocognition of the two memory systems. However, there is also a large literature on techniques that enhance learning and memory. The DP model provides a theoretical framework for predicting which techniques should extend to language learning, and in what circumstances they should apply. In order to lay the neurocognitive groundwork for these predictions, here we first summarize the neurocognitive fundamentals of the two memory systems and briefly lay out the resulting claims of the DP model for both first and second language. We then provide an overview of learning and memory enhancement techniques before focusing on two techniques--spaced repetition and retrieval practice--that have been linked to the memory systems. Next, we present specific predictions for how these techniques should enhance language learning, and review existing evidence, which suggests that they do indeed improve the learning of both first and second language. Finally, we discuss areas of future research and implications for second language pedagogy.

This study investigates the storage vs. composition of inflected forms in typically-developing children. Children aged 8-12 were tested on the production of regular and irregular past-tense forms. Storage (vs. composition) was examined by probing for past-tense frequency effects and imageability effects--both of which are diagnostic tests for storage--while controlling for a number of confounding factors. We also examined sex as a factor. Irregular inflected forms, which must depend on stored representations, always showed evidence of storage (frequency and/or imageability effects), not only across all children, but also separately in both sexes. In contrast, for regular forms, which could be either stored or composed, only girls showed evidence of storage. This pattern is similar to that found in previously-acquired adult data from the same task, with the notable exception that development affects which factors influence the storage of regulars in females: imageability plays a larger role in girls, and frequency in women. Overall, the results suggest that irregular inflected forms are always stored (in children and adults, and in both sexes), whereas regulars can be either composed or stored, with their storage a function of various item- and subject-level factors.

Maternal caregiving capacity, which is affected in part by cognition and mood, is crucial for the health of mothers and infants. Few interventions aim to improve maternal and infant health through improving such capacity. Multiple micronutrient (MMN) supplementation may improve maternal cognition and mood, since micronutrients are essential for brain function. We assessed mothers who participated in the Supplementation with Multiple Micronutrients Intervention Trial (SUMMIT), a double-blind cluster-randomized trial in Indonesia comparing MMN supplementation to iron and folic acid (IFA) during pregnancy and until three months postpartum. We adapted a set of well-studied tests of cognition, motor dexterity, and mood to the local context and administered them to a random sample of 640 SUMMIT participants after an average of 25 weeks (SD = 9) of supplementation. Analysis was by intention to treat. Controlling for maternal age, education, and socio-economic status, MMN resulted in a benefit of 0.12 SD on overall cognition, compared to IFA (95%CI 0.03-0.22, p = .010), and a benefit of 0.18 SD on reading efficiency (95%CI 0.02-0.35, p = .031). Both effects were found particularly in anemic (hemoglobin

The development of complex physical systems, such as scramjets, requires comprehensive assessments of the relevant performance envelopes. Because high-fidelity simulations and experiments are generally too expensive to perform over a wide range of operating conditions, reduced models can be especially useful for exploring the design space. However, these models often involve empirical parameters which must be calibrated using high-fidelity data sets. The present work develops a calibration procedure for a one-dimensional model of the wall pressure in a scramjet flowpath. Using wall pressure measurements from three-dimensional simulations, the six model parameters are tuned using a Bayesian methodology. The results show that the tuned model is largely able to capture the mean wall pressure in both the isolator and combustor. The calibration procedure is able to converge for both uniform and Gaussian priors, provided that the Gaussian priors are sufficiently wide. Physically-consistent correlations between parameters are obtained, which could inform further reductions in the model's dimensionality. Application of the model to additional flow conditions shows good agreement to simulations not used in the calibration procedure. [ABSTRACT FROM AUTHOR]