Bistability and non-Gaussian fluctuations in spontaneous cortical activity. Export

@article{citeulike:5041315, abstract = {The brain is widely assumed to be a paradigmatic example of a complex, self-organizing system. As such, it should exhibit the classic hallmarks of nonlinearity, multistability, and "nondiffusivity" (large coherent fluctuations). Surprisingly, at least at the very large scale of neocortical dynamics, there is little empirical evidence to support this, and hence most computational and methodological frameworks for healthy brain activity have proceeded very reasonably from a purely linear and diffusive perspective. By studying the temporal fluctuations of power in human resting-state electroencephalograms, we show that, although these simple properties may hold true at some temporal scales, there is strong evidence for bistability and nondiffusivity in key brain rhythms. Bistability is manifest as nonclassic bursting between high- and low-amplitude modes in the alpha rhythm. Nondiffusivity is expressed through the irregular appearance of high amplitude "extremal" events in beta rhythm power fluctuations. The statistical robustness of these observations was confirmed through comparison with Gaussian-rendered phase-randomized surrogate data. Although there is a good conceptual framework for understanding bistability in cortical dynamics, the implications of the extremal events challenge existing frameworks for understanding large-scale brain systems.}, author = {Freyer, Frank and Aquino, Kevin and Robinson, Peter A. and Ritter, Petra and Breakspear, Michael}, citeulike-article-id = {5041315}, citeulike-linkout-0 = {http://dx.doi.org/10.1523/JNEUROSCI.0754-09.2009}, citeulike-linkout-1 = {http://www.jneurosci.org/cgi/content/abstract/29/26/8512}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19571142}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19571142}, day = {1}, doi = {10.1523/JNEUROSCI.0754-09.2009}, issn = {1529-2401}, journal = {The Journal of neuroscience : the official journal of the Society for Neuroscience}, keywords = {alpha, human, sponta}, month = {July}, number = {26}, pages = {8512--8524}, posted-at = {2009-07-04 20:51:49}, priority = {2}, title = {Bistability and non-Gaussian fluctuations in spontaneous cortical activity.}, url = {http://dx.doi.org/10.1523/JNEUROSCI.0754-09.2009}, volume = {29}, year = {2009} }

TY - JOUR ID - citeulike:5041315 L3 - citeulike-article-id:5041315 N2 - The brain is widely assumed to be a paradigmatic example of a complex, self-organizing system. As such, it should exhibit the classic hallmarks of nonlinearity, multistability, and "nondiffusivity" (large coherent fluctuations). Surprisingly, at least at the very large scale of neocortical dynamics, there is little empirical evidence to support this, and hence most computational and methodological frameworks for healthy brain activity have proceeded very reasonably from a purely linear and diffusive perspective. By studying the temporal fluctuations of power in human resting-state electroencephalograms, we show that, although these simple properties may hold true at some temporal scales, there is strong evidence for bistability and nondiffusivity in key brain rhythms. Bistability is manifest as nonclassic bursting between high- and low-amplitude modes in the alpha rhythm. Nondiffusivity is expressed through the irregular appearance of high amplitude "extremal" events in beta rhythm power fluctuations. The statistical robustness of these observations was confirmed through comparison with Gaussian-rendered phase-randomized surrogate data. Although there is a good conceptual framework for understanding bistability in cortical dynamics, the implications of the extremal events challenge existing frameworks for understanding large-scale brain systems. IS - 26 JF - The Journal of neuroscience : the official journal of the Society for Neuroscience SN - 1529-2401 EP - 8524 TI - Bistability and non-Gaussian fluctuations in spontaneous cortical activity. VL - 29 SP - 8512 KW - alpha KW - human KW - sponta AU - Freyer, Frank AU - Aquino, Kevin AU - Robinson, Peter AU - Ritter, Petra AU - Breakspear, Michael PY - 2009/07/01/ UR - http://dx.doi.org/10.1523/JNEUROSCI.0754-09.2009 ER -