357 research outputs found

    A large-scale, cross-sectional investigation into the efficacy of brain training

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    Brain training is a large and expanding industry, and yet there is a recurrent and ongoing debate concerning its scientific basis or evidence for efficacy. Much of evidence for the efficacy of brain training within this debate is from small-scale studies that do not assess the type of ā€œbrain training,ā€ the specificity of transfer effects, or the length of training required to achieve a generalized effect. To explore these factors, we analyze cross-sectional data from two large Internet-cohort studies (total N = 60,222) to determine whether cognition differs at the population level for individuals who report that they brain train on different devices, and across different timeframes, with programs in common use circa 2010ā€“2013. Examining scores for an assessment of working-memory, reasoning and verbal abilities shows no cognitive advantages for individuals who brain train. This contrasts unfavorably with significant advantages for individuals who regularly undertake other cognitive pursuits such as computer, board and card games. However, finer grained analyses reveal a more complex relationship between brain training and cognitive performance. Specifically, individuals who have just begun to brain train start from a low cognitive baseline compared to individuals who have never engaged in brain training, whereas those who have trained for a year or more have higher working-memory and verbal scores compared to those who have just started, thus suggesting an efficacy for brain training over an extended period of time. The advantages in global function, working memory, and verbal memory after several months of training are plausible and of clinically relevant scale. However, this relationship is not evident for reasoning performance or self-report measures of everyday function (e.g., employment status and problems with attention). These results accord with the view that although brain training programs can produce benefits, these might extend to tasks that are operationally similar to the training regime. Furthermore, the duration of training regime required for effective enhancement of cognitive performance is longer than that applied in most previous studies

    Dynamic Network Mechanisms of Relational Integration

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    A prominent hypothesis states that specialized neural modules within the human lateral frontopolar cortices (LFPCs) support ā€œrelational integrationā€ (RI), the solving of complex problems using inter-related rules. However, it has been proposed that LFPC activity during RI could reflect the recruitment of additional ā€œdomain-generalā€ resources when processing more difficult problems in general as opposed to RI specifi- cally. Moreover, theoretical research with computational models has demonstrated that RI may be supported by dynamic processes that occur throughout distributed networks of brain regions as opposed to within a discrete computational module. Here, we present fMRI findings from a novel deductive reasoning paradigm that controls for general difficulty while manipulating RI demands. In accordance with the domain- general perspective, we observe an increase in frontoparietal activation during challenging problems in general as opposed to RI specifically. Nonetheless, when examining frontoparietal activity using analyses of phase synchrony and psychophysiological interactions, we observe increased network connectivity during RI alone. Moreover, dynamic causal modeling with Bayesian model selection identifies the LFPC as the effective connectivity source. Based on these results, we propose that during RI an increase in network connectivity and a decrease in network metastability allows rules that are coded throughout working memory systems to be dynamically bound. This change in connectivity state is top-down propagated via a hierarchical system of domain-general networks with the LFPC at the apex. In this manner, the functional network perspective reconciles key propositions of the globalist, modular, and computational accounts of RI within a single unified framework

    An Inquiry Into the Professional Activities of the Iowa Community College President

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    249 leaves. Advisor: Dr. Robert L. WhittThe role of the Community College President can be identified from his activities. The manner in which these roles and responsibilities are handled vary with the setting and the individual performing the activity. This study was made to explore the activities that comprise the role of the Iowa Community College President. The problem. The problems investigated in this study were: 1) How much time does the president spend in performance of certain activities during the school year? 2) How much time do the presidents feel should be spent in each of these activities? 3) What activities do presidents feel are most important to their roles? 4) How do presidents perceive their role in each of the activities? Procedure. A questionnaire identifying sixteen activities of the president was designed and administered to fourteen community college presidents in Iowa. This questionnaire asked for percent of time spent in each activity, percent of time that would be desirable to spend in each activity, the rank in order of importance of each activity, and personal data on training and experience. A taped interview with each of the presidents to discuss perceptions and performance of each of the sixteen activities identified in the study was made. Findings. Findings included: 1) A majority of the presidents had community college experience prior to assuming the presidency, but had prior administrative experience in the public school system. 2) Board-President relationship is a most important task and occupies a considerable amount of the presidents' time. 3) The presidents are highly involved in community affairs. 4) The presidents recognize the importance of institutional planning and are aware that they are not spending a desirable amoumt of time in this activity. 5) There is a moderate positive relationship between time spent and time desirable, indicating that there is a tendency to spend more time on functions where more time is desirable for their performance. 6) There is a moderate positive relationship between the perceived importance of various roles and the time desired for performance. 7) Activities that are viewed as more important are usually performed primarily by the president and activities that are ranked of lesser importance are shared or delegated. Conclusions. Conclusions were: 1) Although there are many similarities in the actual and the perceived role of the presidents of the Iowa area community colleges, there are also significant differences. The similarities can be viewed as the result of the initial state structure and the differences can be viewed as a result of individual differences in the persons and the settings. 2) The roles as determined by the presidents as being more important are not necessarily the roles that occupy the larger amounts of the presidents' time. 3) The most important presidential role, as perceived by the president, is the development and maintenance of a good president-board relationship. Recommendations for Further Study. l) Several of the individual roles included in this study encompass areas of such breadth that an investigation of a singular role would be quite significant. 2) If a more broad role-function research would be desired, desired, an approach similar to the delphi technique would appear to be desirable. 3) The personal and professional characteristics of the occupants of the presidential chair in given area, or of the total United States, would provide important data. 4) A study using roles similar to those used in this investigation, but encompassing a larger geographic area, would be quite useful in determining to what extent the individual and the setting contribute to the overall presidential role function. 5) A study encompassing the managerial skills, with explicit attention to leadership and decision-making, has never been done relative to the community college presidency, to the knowledge of the investigator. Within such a topic area, innumerable opportunities exist for research involving these managerial skills in a broad sense, or with segments of these characteristics involving very specific application

    "It's not rocket science" and "It's not brain surgery"-"It's a walk in the park": prospective comparative study

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    Objective: To compare cognitive testing scores in neurosurgeons and aerospace engineers to help settle the age old argument of which phraseā€”ā€œItā€™s not brain surgeryā€ or ā€œItā€™s not rocket scienceā€ā€”is most deserved. // Design: International prospective comparative study. // Setting: United Kingdom, Europe, the United States, and Canada. // Participants: 748 people (600 aerospace engineers and 148 neurosurgeons). After data cleaning, 401 complete datasets were included in the final analysis (329 aerospace engineers and 72 neurosurgeons). // Main outcome: measures Validated online test (Cognitronā€™s Great British Intelligence Test) measuring distinct aspects of cognition, spanning planning and reasoning, working memory, attention, and emotion processing abilities. // Results: The neurosurgeons showed significantly higher scores than the aerospace engineers in semantic problem solving (difference 0.33, 95% confidence interval 0.13 to 0.52). Aerospace engineers showed significantly higher scores in mental manipulation and attention (āˆ’0.29, āˆ’0.48 to āˆ’0.09). No difference was found between groups in domain scores for memory (āˆ’0.18, āˆ’0.40 to 0.03), spatial problem solving (āˆ’0.19, āˆ’0.39 to 0.01), problem solving speed (0.03, āˆ’0.20 to 0.25), and memory recall speed (0.12, āˆ’0.10 to 0.35). When each groupā€™s scores for the six domains were compared with those in the general population, only two differences were significant: the neurosurgeonsā€™ problem solving speed was quicker (mean z score 0.24, 95% confidence interval 0.07 to 0.41) and their memory recall speed was slower (āˆ’0.19, āˆ’0.34 to āˆ’0.04). // Conclusions: In situations that do not require rapid problem solving, it might be more correct to use the phrase ā€œItā€™s not brain surgery.ā€ It is possible that both neurosurgeons and aerospace engineers are unnecessarily placed on a pedestal and that ā€œItā€™s a walk in the parkā€ or another phrase unrelated to careers might be more appropriate. Other specialties might deserve to be on that pedestal, and future work should aim to determine the most deserving profession

    Systematic review of the behavioural assessment of pain in cats

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    Objectives The objectives were to review systematically the range of assessment tools used in cats to detect the behavioural expression of pain and the evidence of their quality; and to examine behavioural metrics (considering both the sensory and affective domains) used to assess pain. Methods A search of PubMed and ScienceDirect, alongside articles known to the authors, from 2000 onwards, for papers in English was performed. This was followed by a manual search of the references within the primary data sources. Only peer-reviewed publications that provided information on the assessment tool used to evaluate the behavioural expression of pain in cats, in conscious animals (not anaesthetised cats), were included. Results No previous systematic reviews were identified. One hundred papers were included in the final assessment. Studies were primarily related to the assessment of pain in relation to surgical procedures, and no clear distinction was made concerning the onset of acute and chronic pain. Ten broad types of instrument to assess pain were identified, and generally the quality of evidence to support the use of the various instruments was poor. Only one specific instrument (UNESP-Botucatu scale) had published evidence of validity, reliability and sensitivity at the level of a randomised control trial, but with a positive rather than placebo control, and limited to its use in the ovariohysterectomy situation. The metrics used within the tools appeared to focus primarily on the sensory aspect of pain, with no study clearly discriminating between the sensory and affective components of pain. Conclusions and relevance Further studies are required to provide a higher quality of evidence for methods used to assess pain in cats. Furthermore, a consistent definition for acute and chronic pain is needed. Tools need to be validated that can detect pain in a range of conditions and by different evaluators (veterinary surgeons and owners), which consider both the sensory and emotional aspects of pain

    Network mechanisms of intentional learning.

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    The ability to learn new tasks rapidly is a prominent characteristic of human behaviour. This ability relies on flexible cognitive systems that adapt in order to encode temporary programs for processing non-automated tasks. Previous functional imaging studies have revealed distinct roles for the lateral frontal cortices (LFCs) and the ventral striatum in intentional learning processes. However, the human LFCs are complex; they house multiple distinct sub-regions, each of which co-activates with a different functional network. It remains unclear how these LFC networks differ in their functions and how they coordinate with each other, and the ventral striatum, to support intentional learning. Here, we apply a suite of fMRI connectivity methods to determine how LFC networks activate and interact at different stages of two novel tasks, in which arbitrary stimulus-response rules are learnt either from explicit instruction or by trial-and-error. We report that the networks activate en masse and in synchrony when novel rules are being learnt from instruction. However, these networks are not homogeneous in their functions; instead, the directed connectivities between them vary asymmetrically across the learning timecourse and they disengage from the task sequentially along a rostro-caudal axis. Furthermore, when negative feedback indicates the need to switch to alternative stimulus-response rules, there is additional input to the LFC networks from the ventral striatum. These results support the hypotheses that LFC networks interact as a hierarchical system during intentional learning and that signals from the ventral striatum have a driving influence on this system when the internal program for processing the task is updated.This work was supported by Medical Research Council Grant (U1055.01.002.00001.01) and a European Research GrantPCIG13-GA-2013-618351 to AH. JBR is supported by the Wellcome Trust (103838). The authors report no conflicts of interest.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.neuroimage.2015.11.06

    Dust Distribution in Gas Disks. A Model for the Ring Around HR 4796A

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    There have been several model analyses of the near and mid IR flux from the circumstellar ring around HR4796A. In the vicinity of a young star, the possibility that the dust ring is embedded within a residual protostellar gas disk cannot be ruled out. In a gas-rich environment, larger sizes (>100Ī¼m>100 \mu m) are needed for the particles to survive the radiative blow out. The total dust mass required to account for the IR flux is <10āˆ’1MāŠ•< 10^{-1} M_\oplus. The combined influence of gas and stellar radiation may also account for the observed sharp inner boundary and rapidly fading outer boundary of the ring. The pressure gradient induced by a small (10%) amplitude variation in the surface density distribution of a low-mass gaseous disk would be sufficient to modify the rotation speed of the gas.Comment: proof read version, 26 pages, LaTex, 11 figures. To appear in The Astronomical Journal June 200

    Starting a conversation about estimands with public partners involved in clinical trials: a co-developed tool

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    Background: Clinical trials aim to draw conclusions about the effects of treatments, but a trial can address many different potential questions. For example, does the treatment work well for patients who take it as prescribed? Or does it work regardless of whether patients take it exactly as prescribed? Since different questions can lead to different conclusions on treatment benefit, it is important to clearly understand what treatment effect a trial aims to investigateā€”this is called the ā€˜estimandā€™. Using estimands helps to ensure trials are designed and analysed to answer the questions of interest to different stakeholders, including patients and public. However, there is uncertainty about whether patients and public would like to be involved in defining estimands and how to do so. Public partners are patients and/or members of the public who are part of, or advise, the research team. We aimed to (i) co-develop a tool with public partners that helps explain what an estimand is and (ii) explore public partnerā€™s perspectives on the importance of discussing estimands during trial design. Methods: An online consultation meeting was held with 5 public partners of mixed age, gender and ethnicities, from various regions of the UK. Public partner opinions were collected and a practical tool describing estimands, drafted before the meeting by the research team, was developed. Afterwards, the tool was refined, and additional feedback sought via email. Results: Public partners want to be involved in estimand discussions. They found an introductory tool, to be presented and described to them by a researcher, helpful for starting a discussion about estimands in a trial design context. They recommended storytelling, analogies and visual aids within the tool. Four topics related to public partnersā€™ involvement in defining estimands were identified: (i) the importance of addressing questions that are relevant to patients and public in trials, (ii) involving public partners early on, (iii) a need for education and communication for all stakeholders and (iv) public partners and researchers working together. Conclusions: We co-developed a tool for researchers and public partners to use to facilitate the involvement of public partners in estimand discussions

    Tuberculosis in Dr Granville's mummy: a molecular re-examination of the earliest known Egyptian mummy to be scientifically examined and given a medical diagnosis

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    ā€˜Dr Granville's mummyā€™ was described to the Royal Society of London in 1825 and was the first ancient Egyptian mummy to be subjected to a scientific autopsy. The remains are those of a woman, Irtyersenu, aged about 50, from the necropolis of Thebes and dated to about 600 BC. Augustus Bozzi Granville (1783ā€“1872), an eminent physician and obstetrician, described many organs still in situ and attributed the cause of death to a tumour of the ovary. However, subsequent histological investigations indicate that the tumour is a benign cystadenoma. Histology of the lungs demonstrated a potentially fatal pulmonary exudate and earlier studies attempted to associate this with particular disease conditions. Palaeopathology and ancient DNA analyses show that tuberculosis was widespread in ancient Egypt, so a systematic search for tuberculosis was made, using specific DNA and lipid biomarker analyses. Clear evidence for Mycobacterium tuberculosis complex DNA was obtained in lung tissue and gall bladder samples, based on nested PCR of the IS6110 locus. Lung and femurs were positive for specific M. tuberculosis complex cell-wall mycolic acids, demonstrated by high-performance liquid chromatography of pyrenebutyric acidā€“pentafluorobenzyl mycolates. Therefore, tuberculosis is likely to have been the major cause of death of Irtyersenu
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