LabStats

A circuit of evaluation and selection of the alternatives ( see here ) is considered a reliable model in neurobiology. In this published study , valuation and choice of a decisional process during Two-Alternative Forced-Choice ( TAFC ) task are represented as a two-layered network of computational cells, where information accrual and processing progress in nonlinear diffusion dynamics.  The evolution of the response-to-stimulus map is thus modeled by two linked diffusive modules ( 2LDM ) representing the neuronal populations involved in the valuation-and-decision circuit of decision making (Figure 1). Diffusion models are naturally appropriate for describing accumulation of evidence over the time [ see here ] . This allows the computation of the response times (RTs) in valuation and choice, under the hypothesis of ex-Wald distribution. A nonlinear transfer function integrates the activities of the two layers. The input-output map based on the infomax principle makes the 2LD...

Abstract : Eye movement is the simplest and repetitive movement that enables humans to interact with the environment. The common daily activities, such as reading a book or watching television, involve this natural activity, which consists of rapidly shifting our gaze from one region to another. In clinical application, the identification of the main components of eye movement during visual exploration, such as fixations and saccades , is the objective of the analysis of eye movements: however, in patients affected by motor control disorder the identification of fixation is not banal. This work  [ download ]  presents a new fixation identification algorithm based on the analysis of variance and covariance: the main idea was to use bivariate statistical analysis to compare variance over x and y to identify fixation. We describe the new algorithm, and we compare it with the common fixations algorithm based on dispersion. To demonstrate the performance of our approach, we t...

The modified Rankin Scale (mRS) and the Barthel Index (BI) are the most   common clinimetrical instruments for measuring disability after stroke.  This study  [ here ]   investigated the relationship between the BI and the  mRS at multiple time points after stroke.  The BI, which is a widely used instrument for longitudinal follow-up post- stroke, was used as   reference to determine the effect of time on the  sensitivity of the mRS in differentiating   functional recovery.  Methods :  Ninety-two patients with first stroke and hemispheric brain  lesion were evaluated using the BI and mRS at 10 days, 3 and 6 months.  The Kruskal-Wallis test was applied to examine median differences in BI  among the mRS levels at 10 days, 3 and 6 months with Dunn's correction  for multigroup comparison. The Mann and Whitney test was used to  compare median differences in BI scores between two a...

1. Introduction One of the fundamental assumptions of the general linear model 1) y = X β + u where u is a vector of zero-mean and uncorrelated stochastic errors,  is that the data matrix X of order n * k has rank k, that is, the explanatory variables are not linearly dependent. This is because the least squares solution 2)  b = ( X ' X ) -1 X ' y   requires the inversion of X ' X , which, however, would not be possible if the rank of X is <k (because X becomes singular). If  some or all of the explanatory variables are perfectly collinear, then  the system 1)  is said to be affected by " extreme"  multicollinearity .   Problems in the   calculation of the solution 2) can emerge even when the collinearity among the variables is not perfect. the main effects of collinearity are [ 1 ]: Lowered precision of the estimates t hat makes it difficult, if not impossible, to separate the relative influences of ...

Another wave of frost is hitting the United States. The bad weather has caused paralysis of road traffic (with at least 13 deaths from traffic accidents) and the cancellation of about 6,000 flights in the last two days. The more dramatic  situation  is reported in North Carolina, where  because snow and ice have created an immense traffic jam in both directions of  the highway , with thousands of people trapped and hundreds of abandoned cars in the middle of the roadway . Just as had happened two weeks ago near Atlanta , Georgia. Over half a million homes and businesses were left without electricity due to power outage caused by snow and ice. President Barack Obama has declared a state of natural disaster in Georgia and South Carolina, sending federal aid. And the spate of bad weather is moving to the northeast, where heavy snowfalls are expected in Boston, the capital Washington and New York. The scenario is rather catastrophic . In the capital all federal offi...

The results obtained in pre-clinical researchers from the University of Modena and Reggio Emilia (Italy) open hopes in the treatment of disease: hydrogen sulfide and the melanocortin would be able to slow the progression of the Alzheimer's  disease. From the results of research done by the Modena group, coordinated by Salvatore Guarini, Professor of Pharmacology at the Department of Biomedical Sciences, Metabolic and Neuroscience, hydrogen sulphide and melanocortins are able to slow the progression of Alzheimer's disease. Alzheimer's disease is the most common cause of dementia, and without effective treatment, one of the major causes of disability and mortality. Alzheimer's disease is usually diagnosed after the age of 65, while the form of Alzheimer's disease less prevalent, that family or genetic disease, can occur much earlier. The interest of the international scientific community for the originality of the results and the methodological rigor of the s...

The  Bureau of Economic Analysis  ( BEA ) asserts [ here ] :  " Real gross domestic product (GDP) increased 1.7 percent in the second quarter of 2013 after increasing 1.1 percent in the first quarter, according to the “advance” estimate released today [July 31, 2013] by the Bureau of Economic Analysis ( BEA ). "  One would say that the reported growth of the annualized estimate of the U.S. GDP (+1.7%) outperforms the expected result.  We recall that the official GDP is calculated at constant prices, i.e, by applying a deflator to the current values.  In practice, it takes account of the specific rate of inflation in the components of GDP. Obviously the lower the GDP deflator the higher the GDP . Well, the deflator used by the BEA for the second quarter was a tiny +0.71% whilst in the first quarter it was +1.7% and in the last 14 quarters, the U.S. GDP deflator was +1.75% on average. It sounds a bit odd ! If the GDP deflator were wha...