Automaticity and executive abilities in developmental dyslexia: A theoretical review

Cognitive difficulties are well documented in developmental dyslexia but they present a challenge to dyslexia theory. In this paper, the Model of the Control of Action is proposed as a theoretical explanation of how and why deficits in both automaticity and executive abilities are apparent in the cognitive profiles of dyslexia and how these deficits might relate to literacy difficulties. This theoretical perspective is used to consider evidence from different cognitive domains. The neuroanatomical underpinnings of automaticity and executive abilities are then discussed in relation to the understanding of dyslexia. Links between reading, writing, and executive function are considered. The reviewed evidence suggests dyslexia theory should consider an interaction between procedural learned behaviour (automaticity) and higher-order (executive) abilities. The capacity to handle environmental interference, develop and engage adaptive strategies accordingly, and plan actions all require interactions between the cerebellum and the prefrontal cortex (PFC). Difficulties in these areas might explain both impairments in the cumulative development of literacy skills in childhood and general task management in everyday life in adulthood. It is suggested that improved measures are required to assess this cerebellar-PFC interaction and to allow early identification of future literacy difficulties, allowing implementation of timely interventions and reasonable adjustments

CGIAR Climate Change, Agriculture and Food Security Program Theme 3: Pro-Poor Climate Change Mitigation Currently Named: Theme 3: Low Emissions Agriculture. Evaluation of 2011-2013

This document is an evaluation of a component of the CGIAR research program “Climate Change, Agriculture and Food Security” (CCAFS), specifically the program “Pro-poor climate change mitigation” which CCAFS has labeled “Theme 3” and since renamed “Low emissions agriculture.” This evaluation addresses CCAFS Theme 3, from years 2011-13. CCAFS specified that the evaluation will use six criteria: 1. Relevance: Is the Theme 3 program being managed in line with vision in the Program Plan and Theory of Change, and CGIAR reform process, including cross center research, working with partners and consulting with stakeholders in designing research? 2. Effectiveness: How successful is program management at guiding program work to serve program goals, include synergies across activities , involving regional programs, working across scales, and addressing situations that are not going according to plan? 3. Efficiency: Are administrative and transaction costs reasonable? 4. Impact: Are outcomes and incipient outcomes sufficient for a US $10 million per year program? Is low emission development occurring in land use in regions where CCAFS is working? Are women and marginalized groups benefiting? 5. Sustainability of Benefits: Are impacts likely to have continuing benefit for a long time? 6. Quality of Science: For the amount of funding of the program, are there enough high quality publications, and publications in high impact journals

The Effect of Teaching Sixth Graders with Learning Difficulties a Strategy for Solving Verbal Math Problems

This research was published by the KU Center for Research on Learning, formerly known as the University of Kansas Institute for Research in Learning Disabilities.In this study, subjects were taught a seven-step verbal problem-solving strategy. Results indicated an increase in percent correct on eight mathematics word problems for each subject following intervention. Baseline probes never overlapped with treatment probes indicating that generalization is possible to other students in the population studied

The impact of developmental dyslexia on workplace cognition: Evidence from a virtual reality environment

The cognitive difficulties associated with dyslexia persist into adulthood but insights into their impact in employment settings are lacking. A virtual office environment was used to assess two areas of cognition frequently called upon in the workplace, executive function and prospective memory. Eight adults with dyslexia and 27 adults without dyslexia were tested on a virtual office task. They read a scenario describing their new role in an office and were given tasks to complete. The group with dyslexia performed worse overall. On the individual performance measures, the group with dyslexia scored lower on the selective-thinking and planning measures of executive function and also performed worse on two of the three prospective memory measures, namely event-based and time-based prospective memory. The findings indicate how dyslexia can affect workplace cognition, identifying areas in which support might be needed and highlighting areas of relative strength which might be harnessed

The impact of developmental dyslexia on workplace cognition: evidence from a virtual reality environment

The cognitive difficulties associated with dyslexia persist into adulthood but insights into their impact in employment settings are lacking. A virtual office environment was used to assess two areas of cognition frequently called upon in the workplace, executive function and prospective memory. Eight adults with dyslexia and 27 adults without dyslexia were tested on a virtual office task. They read a scenario describing their new role in an office and were given tasks to complete. The group with dyslexia performed worse overall. On the individual performance measures, the group with dyslexia scored lower on the selective-thinking and planning measures of executive function and also performed worse on two of the three prospective memory measures, namely event-based and time-based prospective memory. The findings indicate how dyslexia can affect workplace cognition, identifying areas in which support might be needed and highlighting areas of relative strength which might be harnessed

An X-ray measurement of Titan's atmospheric extent from its transit of the Crab Nebula

Saturn's largest satellite, Titan, transited the Crab Nebula on 5 January 2003. We observed this astronomical event with the {\it Chandra} X-ray Observatory. An ``occultation shadow'' has clearly been detected and is found to be larger than the diameter of Titan's solid surface. The difference gives a thickness for Titan's atmosphere of 880 $\pm$ 60 km. This is the first measurement of Titan's atmospheric extent at X-ray wavelengths. The value measured is consistent with or slightly larger than those estimated from earlier Voyager observations at other wavelengths. We discuss the possibility of temporal variations in the thickness of Titan's atmosphere.Comment: 14 pages, 5 figures, AASTeX preprint. Accepted for publication in the Astrophysical Journa

Children’s Verbal, Visual and Spatial Processing and Storage Abilities: An Analysis of Verbal Comprehension, Reading, Counting and Mathematics

The importance of working memory (WM) in reading and mathematics performance has been widely studied, with recent research examining the components of WM (i.e., storage and processing) and their roles in these educational outcomes. However, the differing relationships between these abilities and the foundational skills involved in the development of reading and mathematics have received less attention. Additionally, the separation of verbal, visual and spatial storage and processing and subsequent links with foundational skills and downstream reading and mathematics has not been widely examined. The current study investigated the separate contributions of processing and storage from verbal, visual and spatial tasks to reading and mathematics, whilst considering influences on the underlying skills of verbal comprehension and counting, respectively. Ninety-two children aged 7- to 8-years were assessed. It was found that verbal comprehension (with some caveats) was predicted by verbal storage and reading was predicted by verbal and spatial storage. Counting was predicted by visual processing and storage, whilst mathematics was related to verbal and spatial storage. We argue that resources for tasks relying on external representations of stimuli related mainly to storage, and were largely verbal and spatial in nature. When a task required internal representation, there was a draw on visual processing and storage abilities. Findings suggest a possible meaningful separability of types of processing. Further investigation of this could lead to the development of an enhanced WM model, which might better inform interventions and reasonable adjustments for children who struggle with reading and mathematics due to WM deficits

Working memory and high-level cognition in children: An analysis of timing and accuracy in complex span tasks

This study examined working memory (WM) using complex span tasks (CSTs) to improve theoretical understanding of the relationship between WM and high-level cognition (HLC) in children. Ninety-two children aged between seven and eight years were tested on three computer-paced CSTs and measures of non-verbal reasoning, reading and mathematics. Processing times in the CSTs were restricted based on individually titrated processing speeds, and performance was compared to participant-led tasks with no time restrictions. Storage, processing accuracy, and both processing and recall times within the CSTs were used as performance indices to understand the effects of time restrictions at a granular level. Restricting processing times did not impair storage, challenging models that argue for a role of maintenance in WM. A task-switching account best explained the effect of time restrictions on performance indices and their inter-relationships. Principal component analysis showed that a single factor with all performance indices from just one CST (Counting span) was the best predictor of HLC. Storage in both the participant-led and computer-paced versions of this task explained unique and shared variance in HLC. However, the latter accounted for more variance in HLC when contributions from processing time were included in the model. Processing time in this condition also explained variance above and beyond storage. This suggests that faster processing is important to keep information active in WM; however, this is only evident when time restrictions are placed on the task and important when WM performance is applied in broader contexts that rely on this resource

In situ rheological measurements of the external gelation of alginate

Direct mixing of alginate and divalent cations such as Ca2+ generally produces heterogeneous gels that form almost instantaneously. Therefore, is particularly difficult to measure the rheological properties of this gelation event due to the rapid gelation kinetics. In this study, the gelation of alginate when exposed to a solution of CaCl2 was measured by using a modified rheometer. This modification involved attaching a petri dish to the lower plate of the rheometer into which, filter paper impregnated with CaCl2 solution was added. A semi-permeable membrane was then placed above the filter paper as a barrier to prevent the filter paper imbibing the gel. Samples of 4%w/w alginate were loaded onto the semi-permeable membrane and measurements were taken using 55mm parallel plate geometry. Measurements of G′ and Gʺ were determined as a function of time to monitor gelation. Once gelation was complete the filter paper was removed and replaced with filter paper impregnated with calcium chelators (EDTA, sodium citrate) to assess the degradation of the gel. The results showed that this technique was suitable for analysing the external gelation of alginate with a sharp increase in G′ in the first three minutes which then plateaued over the remainder of the test. It was also shown that gel stiffness reduced to a greater extent on exposure to EDTA compared with sodium citrate. This method is not only suitable for measuring rapid gelation kinetics on exposure to cross-linkers, but has potential applications in modelling the in situ gelation behaviour in simulated physiological environments