Effects of 24-hour and 36-hour sleep deprivation on smooth pursuit and saccadic eye movements

This is an accepted manuscript of an article published by IOS Press in Journal of Vestibular Research, in 2008. Available online at https://content.iospress.com/articles/journal-of-vestibular-research/ves00326. The accepted version of the publication may differ from the final published version.Sleep restrictions and sleep deprivation have become common in modern society, as many people report daily sleep below the recommended 8 hours per night. This study aimed to examine the effects of sleep deprivation on oculomotor performance by recording smooth pursuit and saccadic eye movements after 24 and 36 hours of sleep deprivation. Another objective was to determine whether detected changes in oculomotor performance followed fluctuations according to a circadian rhythm and/or subjective Visuo-Analogue sleepiness Scale scores. Oculomotor responses were recorded from 18 subjects using electronystagmography, and comprised measurements of accuracy (i.e., the percentage of time the eye movement velocity was within the target velocity boundaries), velocity and latency. Continuous EEG recordings were used to validate that subjects had remained awake throughout the 36-hour period. Our findings showed that sleep deprivation deteriorated smooth pursuit gain, smooth pursuit accuracy and saccade velocity. Additionally, the ratio between saccade velocity and saccade amplitude was significantly decreased by sleep deprivation. However, as the length of sleep deprivation increased, only smooth pursuit gain deteriorated further, whereas there were signs of improvement in smooth pursuit accuracy measurements. The latter observation suggests that smooth pursuit accuracy might be affected by the circadian rhythm of alertness. Surprisingly, high subjective scores of sleepiness correlated in most cases with better saccade performance, especially after 36 hours of sleep deprivation, suggesting that awareness of sleepiness might make subjects perform better during saccade assessments. To conclude, oculomotor function clearly decreased after sleep deprivation, but the performance deteriorations were complex and not necessarily correlated with subjectively felt sleepiness.The authors’ wishes to acknowledge the financial supported from the Swedish Medical Research Council (grant nr. 17x-05693) and the Medical Faculty, Lund University, Sweden. We also acknowledge Janet Lindblad for her invaluable help in the study and Lars Beijer and Fredrik Alvik, ResMed Sweden AB, for providing the Embletta™ EEG measurement equipment for the study

Discussion about Visual Dependence in Balance Control: European Society for Clinical Evaluation of Balance Disorders

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesThe executive committee of the European Society for the clinical evaluation of balance disorders meets annually to address equilibrium problems that are not well understood. This is a review paper on discussions in the latest meeting we held. MATERIALS AND METHODS: Seeing patients with vestibular disorders who end up depending on visual information as part of their compensation process is a common clinical occurrence. However, this "visual dependence" can generate symptoms, which include nausea, sensations of imbalance, and anxiety. It is unclear how this develops, as symptoms can be widely variable from patient to patient. There are several triggering factors to this symptom set, and quantifying it in a given patient is extremely difficult Results: The committee agreed that the presence of this symptom set can be suggestive of vestibular pathology, but the pathology does not have to be present. As a result, there is no correlation between symptom severity and test results. CONCLUSION: Visual dependence can often be present in a patient, although little, if any, measurable pathology is present. It is important to emphasize that although we cannot accurately measure this with either standardized testing or pertinent questionnaires, "hypersensitive" patients have a genuine disease and their symptoms are not of psychiatric origin

An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge

There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance. RESULTS: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization. CONCLUSIONS: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups

From Documents to Data: A Framework for Total Corpus Quality

As large corpora of digitized text become increasingly available, researchers are rediscovering textual datas potential fruitfulness for inquiries into social and cultural phenomena. Although textual corpora promise to enrich our knowledge of the social world, avoiding problems related to data quality remains a challenge to related empirical research. Hence, evaluating the quality of a corpus will be pivotal for future social scientific inquiries. The authors propose a conceptual framework for total corpus quality, incorporating three crucial dimensions: total corpus error, corpus comparability, and corpus reproducibility. These dimensions affect the validity and reliability of inferences drawn from textual data. In addition, the authors framework provides insights toward evaluating and improving studies on the basis of large-scale textual analyses. After outlining this framework, the authors then illustrate an application of the total corpus quality framework by an example case study using digitized newspaper articles to study topic salience over 75 years.Funding Agencies|Swedish Research Council [2018-05170, 2018-06063]; Swiss National Science Foundation [407540_167214]</p

The contribution of mechanoreceptive sensation on stability and adaptation in the young and elderly

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldThe aim was to determine the contributions of foot mechanoreceptive sensation, vision and their interaction on postural stability during quiet stance, balance perturbations and adaptive adjustments. Postural stability was measured as anteroposterior torque variance in Young (n = 25, average age = 25.1 years) and Elderly subjects (n = 16, average age = 71.5 years) during repeated calf vibrations while standing with eyes open and closed. Sensation, recorded using vibration perception and tactile sensitivity, was poorer in elderly than young subjects. Sensation was of low importance for stability during quiet stance and the first 50 s of repeated vibrations, but was associated with stability during the last three 50 s periods of balance perturbations, suggesting that the mechanoreceptive sensation affected how well postural control could adapt to repeated balance perturbations. The findings suggest that clinicians should investigate whether patients with balance problems and poor adaptation have mechanoreceptive sensation deficits

Bayesian leave-one-out cross-validation for large data

Model inference, such as model comparison, model checking, and model selection, is an important part of model development. Leave-one-out cross-validation (LOO-CV) is a general approach for assessing the generalizability of a model, but unfortunately, LOO-CV does not scale well to large datasets. We propose a combination of using approximate inference techniques and probability-proportional-to-size-sampling (PPS) for fast LOO-CV model evaluation for large data. We provide both theoretical and empirical results showing good properties for large data