Almost all models of response time (RT) use a stochastic accumulation process. To account for the benchmark RT phenomena, researchers have found it necessary to include between-trial variability in the starting point and/or the rate of accumulation, both in linear (R. Ratcliff & J. N. Rouder, 1998) and nonlinear (M. Usher & J. L. McClelland, 2001) models. The authors show that a ballistic (dete...

Fields studying movement generation, including robotics, psychology, cognitive science, and neuroscience utilize concepts and tools related to the pervasiveness of variability in biological systems. The concept of variability and the measures for nonlinear dynamics used to evaluate this concept open new vistas for research in movement dysfunction of many types. This review describes innovations...

In many functional-imaging scenarios, four sources contribute to the image formation: the intrinsic variability of the object under study, the variability due to the experimentally controlled stimulus, the state of the equipment, and white noise. These sources are presumably independent, and under a multidimensional Gaussian assumption, Linear Discriminant Analysis is typically used to separate...

Oscillating wind with a period P induce variability with the following characteristics in the upper few hundred meters of the equatorial zone (5øN to 5øS) of the ocean. (1) P < 10 days: these winds fluctuate too rapidly to generate strong currents and excite primarily waves. (2) 10 days < P < 50 days: At these periods the winds generate intense equatorial jets in the upper 50 m, but at greater ...

Methods from nonlinear dynamics (NLD) have shown new insights into heart rate (HR) variability changes under various physiological and pathological conditions, providing additional prognostic information and complementing traditional time- and frequency-domain analyses. In this review, some of the most prominent indices of nonlinear and fractal dynamics are summarized and their algorithmic impl...

In this paper are presented the current results of scientific research of heart rate variability (HRV) analysis based on digital electrocardiograms (ECG). This analysis is a non-invasive and effective technique to reflect the autonomic nervous system regulation of the heart. HRV is used to diagnose and estimate of alterations in heart rate by measuring the variation of RR intervals (time interv...

Purpose. To investigate blood pressure and heart rate variability in patients with primary open-angle glaucoma (POAG) to detect disturbed blood pressure regulation. Methods. Thirty-one patients with POAG (mean age 68 ± 10 years) and 48 control subjects (mean age 66 ± 10 years) were included in a prospective study. Continuous blood pressure and heart rate were simultaneously and noninvasively re...

INTRODUCTION This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". OBJECTIVES The goal of this work is to apply a computational methodology able to characterize mood states in bipolar patients through instantaneous analysis of heartbeat dynamics. METHODS A Point-Proce...