13
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Applications of EEG Neuroimaging Data: Event-related Potentials, Spectral Power, and Multiscale Entropy

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          When considering human neuroimaging data, an appreciation of signal variability represents a fundamental innovation in the way we think about brain signal. Typically, researchers represent the brain's response as the mean across repeated experimental trials and disregard signal fluctuations over time as "noise". However, it is becoming clear that brain signal variability conveys meaningful functional information about neural network dynamics. This article describes the novel method of multiscale entropy (MSE) for quantifying brain signal variability. MSE may be particularly informative of neural network dynamics because it shows timescale dependence and sensitivity to linear and nonlinear dynamics in the data.

          Related collections

          Most cited references15

          • Record: found
          • Abstract: not found
          • Book: not found

          Rhythms of the Brain

            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Nonlinear dynamical analysis of EEG and MEG: review of an emerging field.

            C. Stam (2005)
            Many complex and interesting phenomena in nature are due to nonlinear phenomena. The theory of nonlinear dynamical systems, also called 'chaos theory', has now progressed to a stage, where it becomes possible to study self-organization and pattern formation in the complex neuronal networks of the brain. One approach to nonlinear time series analysis consists of reconstructing, from time series of EEG or MEG, an attractor of the underlying dynamical system, and characterizing it in terms of its dimension (an estimate of the degrees of freedom of the system), or its Lyapunov exponents and entropy (reflecting unpredictability of the dynamics due to the sensitive dependence on initial conditions). More recently developed nonlinear measures characterize other features of local brain dynamics (forecasting, time asymmetry, determinism) or the nonlinear synchronization between recordings from different brain regions. Nonlinear time series has been applied to EEG and MEG of healthy subjects during no-task resting states, perceptual processing, performance of cognitive tasks and different sleep stages. Many pathologic states have been examined as well, ranging from toxic states, seizures, and psychiatric disorders to Alzheimer's, Parkinson's and Cre1utzfeldt-Jakob's disease. Interpretation of these results in terms of 'functional sources' and 'functional networks' allows the identification of three basic patterns of brain dynamics: (i) normal, ongoing dynamics during a no-task, resting state in healthy subjects; this state is characterized by a high dimensional complexity and a relatively low and fluctuating level of synchronization of the neuronal networks; (ii) hypersynchronous, highly nonlinear dynamics of epileptic seizures; (iii) dynamics of degenerative encephalopathies with an abnormally low level of between area synchronization. Only intermediate levels of rapidly fluctuating synchronization, possibly due to critical dynamics near a phase transition, are associated with normal information processing, whereas both hyper-as well as hyposynchronous states result in impaired information processing and disturbed consciousness.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Sample entropy analysis of neonatal heart rate variability.

              Abnormal heart rate characteristics of reduced variability and transient decelerations are present early in the course of neonatal sepsis. To investigate the dynamics, we calculated sample entropy, a similar but less biased measure than the popular approximate entropy. Both calculate the probability that epochs of window length m that are similar within a tolerance r remain similar at the next point. We studied 89 consecutive admissions to a tertiary care neonatal intensive care unit, among whom there were 21 episodes of sepsis, and we performed numerical simulations. We addressed the fundamental issues of optimal selection of m and r and the impact of missing data. The major findings are that entropy falls before clinical signs of neonatal sepsis and that missing points are well tolerated. The major mechanism, surprisingly, is unrelated to the regularity of the data: entropy estimates inevitably fall in any record with spikes. We propose more informed selection of parameters and reexamination of studies where approximate entropy was interpreted solely as a regularity measure.
                Bookmark

                Author and article information

                Journal
                J Vis Exp
                J Vis Exp
                JoVE
                Journal of Visualized Experiments : JoVE
                MyJove Corporation
                1940-087X
                2013
                27 June 2013
                27 June 2013
                : 76
                : 50131
                Affiliations
                Rotman Research Institute, Baycrest
                Author notes

                Correspondence to: Jennifer J. Heisz at jheisz@ 123456research.baycrest.org

                Article
                50131
                10.3791/50131
                3729183
                23851571
                3a2cd82b-d561-4ad2-b9e7-c70573fe0fd3
                Copyright © 2013, Journal of Visualized Experiments

                This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial License, which permits non-commercial use, distribution, and reproduction, provided the original work is properly cited.

                History
                Categories
                Neuroscience

                Uncategorized
                neuroscience,issue 76,neurobiology,anatomy,physiology,medicine,biomedical engineering,electroencephalography,eeg,electroencephalogram,multiscale entropy,sample entropy,meg,neuroimaging,variability,noise,timescale,non-linear,brain signal,information theory,brain,imaging

                Comments

                Comment on this article