Simple Visual Test Research Articles

The Effect of Spatial Uncertainty on Visual Search in Older School-Aged Children with and without ADHD.

Numerous studies support that simple visual search tests may not be sufficient to differentiate children with and without attention-deficit/hyperactivity disorder (ADHD), especially for older school-aged children. This study aimed to explore whether the high spatial uncertainty visual search tasks can effectively discriminate older school-aged children with ADHD from their typically developing (TD) peers. In a randomized, two-period crossover design, 122 school-aged children (61 ADHD and 61 TD subjects), aged 10-12years old, were measured using comparable visual search tasks with structured and unstructured layouts. First, the discriminant effectiveness of unstructured visual search tasks, which are associated with high-level spatial uncertainty, is superior to structured ones. Second, combining accuracy and speed into a Q score is a more sensitive measure than accuracy or time calculated alone in visual search tasks. A more in-depth ROC analysis showed that all variables could accurately identify ADHD from their TD peers under unstructured visual search tasks, with the index of the Q score performing best (AUR = 0.956). Third, the development of detectability, which represents the ability to distinguish between target and non-target, is approaching maturity in 10-12-year-old children with ADHD. However, these children showed severe deficits in dealing with disorganized distractors when performing visual search tasks with high-level spatial uncertainty. The findings of this study support that older school-aged children with ADHD demonstrate less efficient search performance than their TD peers in complex/difficult visual search tasks, especially under higher spatial uncertainty.

A Simple, Affordable, and Rapid Visual CRISPR-Based Field Test for Sex Determination of Earlier Porcine Embryos and Pork Products.

Sex selection technologies have immensely impacted swine production globally. Conventional earlier embryo sex identification methods require professional technicians and sophisticated laboratory instruments. Rapid on-site gender identification of porcine embryos and pork products remains challenging. In this study, we developed a CRISPR/Cas12a-based fluorescence visualization point-of-care sex determination test that is rapid, accurate and easy to implement on-site. The CRISPR/Cas12a assay coupled with either the polymerase chain reaction (PCR) or loop-mediated isothermal amplification (LAMP) employs precisely designed primers and single-guide RNAs targeting the sex-determining region Y (SRY) and the zinc finger protein X-linked (ZFX) genes. PCR and LAMP amplicons were cleaved with the subsequent generation of fluorescing products detectable with portable blue and ultraviolet light transilluminators. Approximately two copies per microliter of the ZFX and SRY genes were detected using the RApid VIsual CRISPR (RAVI-CRISPR) assay. This method is a sensitive, inexpensive, versatile, and point-of-care test. The technology has other potential applications like determining the sex of diverse livestock species, detecting livestock disease-causing pathogens and evaluating the quality of meat products.

The dynamic optotype (Dyop): a novel visual acuity test for use in children

To evaluate the "dynamic optotype" (Dyop), a simple visual acuity test based on a dynamic target that requires minimal knowledge of symbols and letters. A total of 160 consecutive, systemically healthy children, 4-17years of age were prospectively recruited from the Pediatric Ophthalmology Unit of Meir Medical Center. Children were tested with the Dyop visual acuity test and the Early Treatment Diabetic Retinopathy Study (ETDRS) Lea numbers chart. The results of both tests were compared. The eye with the poorest acuity was tested with the new Dyop eye chart and the Lea numbers chart. The order of the testing was reversed between children. The logMAR visual acuity scores for each eye chart were compared. We found a strong linear correlation (r=0.88) between visual acuity measures. The mean difference in visual acuity was -0.01 (95% CI, -0.02 to 0.01). The 95% limits of agreement were ±1.2 lines. The logMAR equivalent mean difference was about less than 1 letter. The Dyop test underestimated visual acuity relative to the Lea numbers chart. The results of this study support the Dyop eye chart as a valid measure of visual acuity in children 4-17years of age, with visual acuity ranging from 20/16 to 20/200.

Unreliability of Available Pseudorandom Number Generators

The problem of generating sequences of uniformly distributed pseudorandom numbers is considered. A simple visual test for estimating the randomness of numbers in a sequence is used. The test shows that the most popular modern random number generators, such as the Mersenne Twister, linear congruential sequence, and others, yield unsatisfactory results. Accordingly, the generation of good generators remains an open problem, and results of computing stochastic processes (molecular dynamics method, etc.) have to be treated with caution.

Rapid Identification of Saber Steel Flexibility, Microhardness, and Chemical Composition by Analyzing Electromagnetic Signatures

Modern fencing sabers are made of composite steel alloys. Although there are regulations standardizing blade dimensions and stiffness, fencers often find blades having variable flexibility and tensile strength from vendor to vendor and, occasionally, from batch to batch of production. Due to the absence of an objective test to assess blade quality, fencers often resort to testing blades with simple visual or physical whip tests. These manual blade assessments, however, are unsatisfactory due to subjective inconsistencies as well as unreliability due to similar blade weights, colors, and appearances. The ability to properly and accurately test blade quality is of utmost importance, not only for competition, but more importantly, to prevent injuries which have occurred as a result of broken blades. Traditional industrial methods of steel alloy identification involve spectrometry or machine tensile strength assessments, which are both destructive to the blade and impractical in a competition arena. We previously reported a method to use the smartphone magnetometer to differentiate fencing steel alloys. This manuscript now demonstrates the correlation between electromagnetic signatures to the flexibility, microhardness and chemical composition of steel blades.

Shortened Measurement Time of Functional Visual Acuity for Screening Visual Function.

The functional visual acuity test which is the average of the visual acuities measured during a specific time frame (standard, 60 seconds) has been used recently to assess the visual function in various conditions. The availability of a shorter version of the functional visual acuity test promises to be patient friendly in that it is a simple screening test performed in a shorter period of time than the standard test. The results of measurements of the FVA test between the 30-second measurement time (short-version FVA test) and the standard 60-second measurement are compared, and the feasibility of the short-version FVA test instead of the standard FVA test is investigated. Twenty-eight healthy volunteers (25 men and 3 women) were enrolled in this prospective observational study. All subjects underwent measurement of the binocular distance-corrected visual acuity and the binocular distance-corrected FVA with the 60-second and 30-second measurement times. The interchangeability of the corrected-distance FVA, maximal VA, visual maintenance ratio, and average response time in the short-version and the standard FVA tests was evaluated using the Bland–Altman method, and the results showed agreements of the two tests except for the minimal VA. The short-version FVA test is equivalent to the standard method except for evaluating the visual acuity fluctuations and promises to be a simple visual screening test that can be performed in a shorter time.

Exaggerated blood pressure variability is associated with memory impairment in very elderly patients.

We investigated the association between working memory (WM) impairment and blood pressure variability (BPV) in very elderly patients. Japanese outpatients ≥80years who engaged in normal activities of daily living were the study cohort. WM function was evaluated by a simple visual WM test consisting of 3 figures. We considered the number of figures recalled by the patient his/her test score. We defined the patients with a score of 0 or 1 as those with WM impairment and those with scores of 2 or 3 as those without. To investigate the relative risk of WM impairment, we evaluated each patient's 24hour ambulatory systolic blood pressure (SBP) and its weighted standard deviation (SDSBP ), office SBP, and the visit-to-visit SDSBP during the 1year period from the patient's enrollment. A total of 66 patients (mean 84±3.6years) showed WM impairment, and 431 patients (mean 83±3.1years) showed no WM impairment. There were no significant differences in 24hour ambulatory SBP or office SBP between these two groups. However, the WM impairment patients showed significantly higher weighted SDSBP and visit-to-visit SDSBP values compared to the no-impairment group even after adjusting for age. Among these ≥80-year-old patients, those with the highest quartile of both weighted SDSBP (≥21.4mmHg) and visit-to-visit SDSBP (≥14.5mmHg) showed the highest relative risk (odds ratio 3.52, 95% confidence interval 1.42-8.72) for WM impairment. Exaggerated blood pressure variability parameters were significantly associated with working memory impairment in very elderly individuals.

Driving performance comparing older versus younger drivers

ABSTRACTObjectives: A cross-sectional study was conducted at the Touro University California campus to compare differences in reaction times and driving performance of younger adult drivers (18–40 years) and older adult drivers (60 years and older). Each test group consisted of 38 participants.Methods: A Simple Visual Reaction Test (SVRT) tool was used to measure reaction times. The STISIM Drive M100 driving simulator was used to assess driving parameters. Driving performance parameters included mean lane position, standard deviation of mean lane position measured, mean speed, standard deviation of mean speed, car-following delay, car-following modulus, car-following coherence, off-road accidents, collisions, pedestrians hit, and traffic light tickets.Results: Compared to younger participants, older drivers experienced significantly slower reaction times (510.0 ± 208.8 vs. 372.4 ± 96.1 ms, P =.0004), had more collisions (0.18 ± 0.39 vs. none, P =.0044), drove slower (44.6 ± 6.6 vs. 54.9 ± 11.7 mph, P <.0001), deviated less in speed (12.6 ± 4.3 vs. 16.8 ± 6.3, P =.0011), and were less able to maintain a constant distance behind a pace car (0.42 ± 0.23 vs. 0.59 ± 0.24; P =.0025).Conclusions: Differences exist in driving patterns of older and younger drivers as measured by reaction times and driving simulator outcomes. These results are the first to compare these 2 specific adult age groups' driving performance as measured by a standardized driving simulator scenario. Identifying these differences is essential in addressing them and preventing future traffic injuries.

Evaluation and Acceptability of a Simplified Test of Visual Function at Birth in a Limited-Resource Setting.

Neurological examination, including visual fixation and tracking of a target, is routinely performed in the Shoklo Malaria Research Unit postnatal care units on the Thailand-Myanmar border. We aimed to evaluate a simple visual newborn test developed in Italy and performed by non-specialized personnel working in neonatal care units. An intensive training of local health staff in Thailand was conducted prior to performing assessments at 24, 48 and 72 hours of life in healthy, low-risk term singletons. The 48 and 72 hours results were then compared to values obtained to those from Italy. Parents and staff administering the test reported on acceptability. One hundred and seventy nine newborns, between June 2011 and October 2012, participated in the study. The test was rapidly completed if the infant remained in an optimal behavioral stage (7 ± 2 minutes) but the test duration increased significantly (12 ± 4 minutes, p < 0.001) if its behavior changed. Infants were able to fix a target and to discriminate a colored face at 24 hours of life. Horizontal tracking of a target was achieved by 96% (152/159) of the infants at 48 hours. Circular tracking, stripe discrimination and attention to distance significantly improved between each 24-hour test period. The test was easily performed by non-specialized local staff and well accepted by the parents. Healthy term singletons in this limited-resource setting have a visual response similar to that obtained to gestational age matched newborns in Italy. It is possible to use these results as a reference set of values for the visual assessment in Karen and Burmese infants in the first 72 hours of life. The utility of the 24 hours test should be pursued.

Effects of valerian on subjective sedation, field sobriety testing and driving simulator performance

IntroductionThe availability of herbal medicines over-the-counter (OTC) has increased the use of natural products for self-treatment. Valerian has been used to effectively treat generalized anxiety disorder and insomnia. Studies suggest that valerenic acid may increase gamma-aminobutyric acid (GABA) modulation in the brain. Benzodiazepines have a similar mechanism of action and have been linked to an increased risk of hospitalizations due to traffic accidents. Despite the risk of somnolence, the safety of driving while under the influence of valerian remains unknown. PurposeThe purpose of the study was to determine the effects of a one-time valerian 1600mg dose on subjective sedation effects, standardized field sobriety testing (SFST) and driving simulator performance parameters. MethodsThe study design was a randomized, placebo-controlled, double-blind, cross-over trial. For each session, participants received either a dose of valerian or placebo. The outcome measures included a simple visual reaction test (SVRT), subjective sleepiness scales, SFST performance scores, and driving simulator performance parameters. ResultsThere were no significant differences in the SVRT or sleepiness scales between placebo and valerian exposures, but the study may have been underpowered. SFST total and individual test failure rates were not significantly different between the two exposures. The driving simulator performance parameters were equivalent between the two exposure conditions. ConclusionsA one-time valerian 1600mg dose, often used to treat insomnia, does not appear to impair driving simulator performance after acute ingestion.

OC-0168: A simple visual test is adequate for testing vmDIBH reproducibility in locoregional breast cancer

Purpose or Objective: Voluntary moderately deep inspiration breath hold (vmDIBH) reduces the heart dose for radiotherapy of left-sided breast cancer patients. For locoregional breast cancer patients, the application of vmDIBH requires high reproducibility to assure the absence of gap or overlay between tangential breast fields and supraclavicular irradiation fields. In this study we present a simple and fast visual method to quantify movement around the junction of the tangential and supraclavicular fields. The simple method is evaluated by testing the target volume reproducibility using two consecutive CT-scans during vmDIBH. Heart position reproducibility is assessed as well, with the resulting dosimetric consequences. Material and Methods: For 80 consecutive breast cancer patients cranial-caudal (CC) displacement around the clavicle was quantified between five vmDIBHs. This was done in the CT room, before obtaining the planning Ct scan. Intersecting CT laser lines were marked on tape and the maximum displacement was measured. This tape was positioned midclavicularly, with the horizontal laser lines on the junction line. For 19 patients who woud be irradiated locoregionally, a second CT scan was additionally acquired. The CC displacement of the left clavicle between the two breath holds was quantified by contouring the left clavicle in both CT scans, and rigid registration of the two volumes in ProSoma (v.3.3.266, Medcom, Darmstadt, Germany) virtual simulation software. The heart was delineated in both CT scans, excluding the great vessels. The two volumes were registered in ProSoma to measure CC, left-right (LR) and anterior-posterior (AP) displacements. Influence of the heart displacement on dosimetry was measured by superimposing the contoured heart volume of the second CT scan onto the treatment planning CT scan and calculating mean heart dose. Results: Results of the tape test show a mean CC displacement of 3.3 mm (range 0.5-0.8 mm) for the midclavicular region. For the two breath hold CT scans mean CC clavicle displacement was 1.1 mm (range 0.1-2.8 mm). The measured CC displacements of the tape test were for all 19 locoregional patients larger than measured with CT. Mean difference in contoured heart volume was 3.7% (range 0.5-11.2%). Mean heart dose differed on average 0.12 Gy (range 0.01-0.38 Gy), where planned mean heart dose varied between 0.59 and 3.58 Gy. MEan heart displacement was 1.7 mm (range 0-4.7 mm) CC, 1.5 mm (range 0.1-4.2 mm) AP and 1.9 mm (range 0.11-6.9 mm) LR. Conclusion: A simple visual test is a good surrogate for CT scans in analyzing vmDIBH reproducibility. We showed that vmDIBH is reproducible with minimal gap or overlay between the tangential and supraclavicular fields, allowing for implementation of vmDIBH in locoregionally irradiated patients. Heart position variation is limited to 2 mm and dose variation to 0.4 Gy, between sequential breath holds for most patients.

Impact of Hepatitis C Virus Infection on Cognitive Function in Patients With Covert Hepatic Encephalopathy.

Background:Liver cirrhosis has a significant impact on patient’s quality of life and socioeconomic status and is associated with increased susceptibility to vehicle accidents and falls.Objectives:This study was conducted to evaluate cognitive function in patients with cirrhosis.Patients and Methods:All subjects, who underwent transient elastography (TE) between March 2014 and August 2014 in Shariati outpatient clinic, Tehran, Iran, were enrolled in the study. The diagnosis of cirrhosis was made based on clinical and laboratory findings and liver stiffness measurement (LSM) values > 14. Wechsler Memory Scale (WMS) and simple visual reaction time (RT) were the neuropsychiatric tests used to assess cognitive function, in all subjects.Results:A total of 37 cirrhotic patients and 37 matched controls were included. Patients with cirrhosis had significantly lower mean quotient (MQ) score, compared with controls (91 ± 18.2 vs. 114.6 ± 17.5, P <0.001). All of WMS subscales, except associate learning, showed statistically significant differences between the two groups. Reaction time was more prolonged in patients with cirrhosis, compared with controls. Cognitive function of hepatitis C virus (HCV) patients was significantly impaired, with respect to logical memory, visual reproduction and MQ score, compared to other underlying causes of cirrhosis (P = 0.01, P = 0.04, and P = 0.01, respectively)Conclusions:Our results suggested that neuropsychiatric and cognitive problems must be considered in the management of covert hepatic encephalopathy (HE) patients, especially in patients with HCV infection. The WMS and simple visual RT tests are useful methods for the early diagnosis of covert HE.

Order and Chaos in the Brain: Fractal Time Series Analysis of the EEG Activity During a Cognitive Problem Solving Task

The study of brain dynamics has been approached from different mathematical strategies with the aim to obtain more information of the bioelectrical signals coming from an electroencephalogram (EEG). Although several of these tools try to conciliate the fact of using linear approaches to study a non-linear phenomenon, during the last years a set of complementary and alternative approaches has been used to mine deeper into the nature of the brain dynamics and its correlates with experience, thoughts and actions. One of these approaches comes from chaos theory and fractal geometry and considers a model where brain activity, as a time series of an electrical potential variation (EEG) recorded from the scalp, can be assumed as a dynamical state that moves in the range of 1/f α (fractal) noise. In this model it is possible to see brain dynamics as a functional state who moves from more chaotic or unpredictable dynamics (Brown or Gaussian uncorrelated noise), to quasi-chaotic or statistical noise (fractal or self-similar noise). The amount of order into the chaotic EEG background must be an indicator of the organization of brain procedural resources dealing with different circumstances. At the same time, it must reflect the degree of inter-individual differences and intra-individual variability in the way each different brain works. To test this hypothesis we implemented a study where EEG activity was recorded during the performing of a simple visual intelligent test (Raven test, abbreviated version of 15 questions) in a set of 10 adults to study their similarities and differences in the rendering of the test (estimated range of IQ) and in the process of solving the easy and the difficult part of the test. We estimated the Hurst exponent and the fractal dimension of the time series for each of the 14 EEG channels (Emotiv-Epoc® BCI headset) and searched for correlations and consistencies in the values of H and the difficulty level of the cognitive task. We found that order tend to emerge from a chaotic background when brain focuses on problem solving, rising the degree of predictability, self-similarity and persistent behavior of the EEG signal.

Convergent validity of the measures of attention and impulsivity in the Trees: Simple Visual Discrimination Test (DiViSA-UAM). [Validez convergente de las medidas de atención e impulsividad del Test de Discriminación Visual Simple de Árboles (DiViSA-UAM)

The Trees: Simple Visual Discrimination Test (DiViSA-UAM) is an objective test to assess attention and impulsivity in children aged between 6 and 12 years. The aim of this study was to supplement the validity data ob- tained in prior research, analyzing the evidence of convergent validity of the measures of the DiViSA-UAM in relation to other, already well- established, instruments for assessing attention and inhibitory control in children: the 'Faces', Differences Perception Test and the d2 Test of Attention. To this end, the instruments were administered to a sample of 111 students from primary education (46 girls and 65 boys) between the ages of 8 and 12 years. The correlation analysis showed values in line with expectations among the indices of the three tests. Similarly to what has been observed in prior research, the three tests coincided in identifying a progressive increase in attention performance between the ages of 8 and 12, as well as stability in impulsivity control and the absence of sex-related differences. We dis- cuss the potential advantages of the DiViSA-UAM derived from its appli- cation format and its greater ease of execution.

A Bayesian and Emergent View of the Brain

Very simple psychophysiological visual tests suggest that the brain, instead of processing visual information in a passive way as was classically thought, in fact actively evaluates probabilities of the causes of visual data and continuously proposes to the mind the ones that are more likely to account for sensory inputs. In the past few years, Karl Friston, a researcher from University College of London, and his group have proposed a mechanism by which the brain successfully performs with great precision the inversion of probability densities necessary for this Bayesian computation. This mechanism would account for several anatomic structures of the cortex, explaining in particular the abundance of backwards interneuronal connections. The proposed picture of brain functioning is that of a dynamical process, far from the static image of a photographic plate. The result is an emergence, for the final picture of the world is a coherent vision where the more likely causes are proposed in a coherent manner. Although the theory accounts for the automatic, infraconscious side of the processing of information in the brain, it is in good accord with Roger Sperry’s theory of consciousness as a theory of strong emergence. It is too soon to evaluate the solidity of the law of “minimization of free energy” proposed by Friston not only as ruling the automatisms of the brain but as a general law of biology. This law is similar (although in contradistinction) to the second law of thermodynamics of increase of entropy (insofar as it explains the tendency of living beings for self-organization), and it is already looked at by some neuroscientists as a big step forward in deciphering the mysteries of the brain.

The diagnostic accuracy of Neuropad for assessing large and small fibre diabetic neuropathy.

Neuropad is a simple visual indicator test, with moderate diagnostic performance for diabetic peripheral neuropathy. As it assesses sweating, which is a measure of cholinergic small nerve fibre function, we compared its diagnostic performance against established measures of both large and, more specifically, small fibre damage in patients with diabetes. One hundred and twenty-seven participants (89 without diabetic peripheral neuropathy and 38 with) aged 57 ± 9.7 years underwent assessment with Neuropad, large nerve fibre assessments: Neuropathy Disability Score, vibration perception threshold, peroneal motor nerve conduction velocity; small nerve fibre assessments: neuropathy symptoms (Diabetic Neuropathy Symptoms score) corneal nerve fibre length and warm perception threshold. Neuropad has a high sensitivity but moderate specificity against large fibre neuropathy assessments: Neuropathy Disability Score (> 2) 70% and 50%, vibration perception threshold (> 14 V) 83% and 53%, and peroneal motor nerve conduction velocity (< 42 m/s) 81% and 54%, respectively. However, the diagnostic accuracy of Neuropad was significantly improved against corneal nerve fibre length (< 14 mm/mm2) with a sensitivity and specificity of 83% and 80%, respectively. Furthermore, the area under the curve for corneal nerve fibre length (85%) was significantly greater than with the Neuropathy Disability Score (66%, P = 0.01) and peroneal motor nerve conduction velocity (70%, P = 0.03). For neuropathic symptoms, sensitivity was 78% and specificity was 60%. The data show the improved diagnostic performance of Neuropad against corneal nerve fibre length. This study underlines the importance of Neuropad as a practical diagnostic test for small fibre neuropathy in patients with diabetes.

PENGEMBANGAN UJI VISUAL SEDERHANA DARI KUALITAS BERBAGAI KOMPOS DAN PERBANDINGANNYA DENGAN UJI LABORATORIUM DAN UJI PERCOBAAN LAPANGAN

At the market, composts are sold varied in their quality. Some of them are originated fromforest floor and other are collected from burnt and half- decomposed municipal waste. Thereis no control for commercial compost by government, thus many of composts sell at marketare not registered. Buyers should able to detect the good and bad compost quality in thesimple ways. This present experiment was conduct to develop a new simple visual test todetect the good and bad compost quality and comparing test result with the test result oflaboratory analysis and field experiment. The composts used in this experiment were:vermicompost (made by researcher), 2 burnt municipal waste (burned by researcher) and 8commercial composts. Simple test consist of several parameters viz color, odor, react ofcompost when put into water, The compost laboratory analysis were: pH, carbon organic,total nitrogen, ratio, C/N, total microorganism number, water holding capacity, compostparticle size composition. The field experiment test was conducted in the screen house usingmustard as an indicator plant. The experiment design was randomized block with 12treatments (vermicompost as a control for good compost, 2 burnt municipal waste compostsas a control for bad compost, 8 commercial composts and without adding compost) and 3replications. The result showed that the color of burnt municipal waste composts weregrayish, while the color of vermicompost was dark brown. No Odor of burnt municipalwaste compost was founds, while the odor of vermicompost was humid odor. All of theburnt municipal waste composts were sinking into the bottom of glass when it puted intowater, and not for vermicompost. Almost all of compost solid from forest floor was floatingwhen puted into water. The laboratory analysis test showed the burnt municipal compostshad the lowest C organic, N total content, C/N, and total microorganism number, and had thehighest pH value compare to other composts. The tests showed that some of commercialcomposts quality were bad. Meanwhile, the result of field experiment test did not gave thesignificant effect on the growth and production of mustard (Brassica juncea) using good orbad compost quality compare to control (without adding compost). As conclusion, the badquality of compost especially the burnt municipal waste compost, and the forest floorcompost were able detect using simple test by putting it into water.Keywords : vermicompost, burnt municipal waste, commercial compost, simple test,laboratory test, field experiment test

Dysconnectivity in the frontoparietal attention network in schizophrenia.

Cognitive impairment is common in patients with schizophrenia, and even those with relatively preserved function perform worse than healthy volunteers (HVs) on attentional tasks. This is consistent with the hypothesis that connectivity – in the frontoparietal network (FPN) activated during attention – is disrupted in schizophrenia. We examined attentional effects on connectivity in the FPN, in schizophrenia, using magnetoencephalography (MEG). Twenty-three HVs and 19 first-episode schizophrenia patients were scanned during a simple visual change test, known to activate the FPN, in which attention was monitored and directed with an orthogonal flicker-detection task. Dynamic causal modeling (DCM) of evoked responses was used to assess effective connectivity – and its modulation by changes in the attended stimulus dimension – in the following network: higher visual area; temporoparietal junction (TPJ); intraparietal sulcus (IPS); dorsal anterior cingulate cortex; and ventrolateral prefrontal cortex. The final MEG analysis included 18 HVs and 14 schizophrenia patients. While all participants were able to maintain attention, HVs responded slightly, but non-significantly, more accurately than schizophrenia patients. HVs, but not schizophrenia patients, exhibited greater cortical responses to attended visual changes. Bayesian model comparison revealed that a DCM with attention dependent changes in both top-down and bottom-up connections best explained responses by patients with schizophrenia, while in HVs the best model required only bottom-up changes. Quantitative comparison of connectivity estimates revealed a significant group difference in changes in the right IPS-TPJ connection: schizophrenia patients showed relative reductions in connectivity during attended stimulus changes. Crucially, this reduction predicted lower intelligence. These data are consistent with the hypothesis that functional dysconnections in the FPN contribute to cognitive impairment in schizophrenia.

Recognition of stable distribution with Lévy indexαclose to 2

We address the problem of recognizing α-stable Lévy distribution with Lévy index close to 2 from experimental data. We are interested in the case when the sample size of available data is not large, thus the power law asymptotics of the distribution is not clearly detectable, and the shape of the empirical probability density function is close to a Gaussian. We propose a testing procedure combining a simple visual test based on empirical fourth moment with the Anderson-Darling and Jarque-Bera statistical tests and we check the efficiency of the method on simulated data. Furthermore, we apply our method to the analysis of turbulent plasma density and potential fluctuations measured in the stellarator-type fusion device and demonstrate that the phenomenon of the L-H transition from low confinement, L mode, to a high confinement, H mode, which occurs in this device is accompanied by the transition from Lévy to Gaussian fluctuation statistics.

Useful Application of the Neuropad Test for Assessment of Diabetic Polyneuropathy

Examination of sudomotor function is now recommended to assess peripheral autonomic dysfunction. The aim of this study was to evaluate the clinical usefulness of Neuropad, a simple visual indicator test, for assessment of diabetic polyneuropathy (DPN). This study examined 87 diabetic patients with a mean age of 61.1±8.8 years, a mean diabetes duration of 13.0±7.5 years and a mean HbA1c of 8.8±1.7%. Diagnosis of DPN was based on clinical examinations using modified Toronto Clinical Neuropathy Score (mTCNS). The patients also underwent 4-g monofilament test and heart rate variability by coefficient of variation of R-R intervals (CV(R-R)) was determined with the patients at rest. The Neuropad test was applied on the plantar aspect of the great toe and removed after 10 minutes to evaluate the color change as normal (blue to completely pink), patchy (patches of blue and pink) and abnormal (remained blue). Twenty-eight patients showed a normal, 45 patchy and 14 abnormal response to the Neuropad test. Patients with an abnormal response had significantly longer diabetes duration than those with a normal or a patchy response, but HbA1c levels were similar among the three groups. The C(R-R) at rest was significantly lower in patients with an abnormal response than those of normal and patchy response, respectively. Abnormal responders showed significantly higher mTCNS and lower monofilament results as well as higher prevalence of orthostatic hypotension, retinopathy or nephropathy than normal responders. The Neuropad test is a useful screening test for detecting DPN.