0000000000319410

AUTHOR

Plamen Ch. Ivanov

0000-0001-7629-762x

showing 4 related works from this author

Entropy measures, entropy estimators, and their performance in quantifying complex dynamics: Effects of artifacts, nonstationarity, and long-range co…

2017

Entropy measures are widely applied to quantify the complexity of dynamical systems in diverse fields. However, the practical application of entropy methods is challenging, due to the variety of entropy measures and estimators and the complexity of real-world time series, including nonstationarities and long-range correlations (LRC). We conduct a systematic study on the performance, bias, and limitations of three basic measures (entropy, conditional entropy, information storage) and three traditionally used estimators (linear, kernel, nearest neighbor). We investigate the dependence of entropy measures on estimator- and process-specific parameters, and we show the effects of three types of …

Conditional entropyStatistics and ProbabilityDynamical systems theoryComputer scienceEstimatorCondensed Matter Physics01 natural sciencesArticlek-nearest neighbors algorithm03 medical and health sciencesComplex dynamics0302 clinical medicineAutoregressive modelLocal variance0103 physical sciencesStatisticsSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaPreprocessorStatistical physics010306 general physics030217 neurology & neurosurgeryStatistical and Nonlinear PhysicPhysical review. E
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Network Physiology of Cortico–Muscular Interactions

2020

Skeletal muscle activity is continuously modulated across physiologic states to provide coordination, flexibility and responsiveness to body tasks and external inputs. Despite the central role the muscular system plays in facilitating vital body functions, the network of brain-muscle interactions required to control hundreds of muscles and synchronize their activation in relation to distinct physiologic states has not been investigated. Recent approaches have focused on general associations between individual brain rhythms and muscle activation during movement tasks. However, the specific forms of coupling, the functional network of cortico-muscular coordination, and how network structure a…

Flexibility (anatomy)Computer sciencePhysiologybrain wavesPhysiologynetwork physiologylcsh:Physiology03 medical and health sciencesMuscle tone0302 clinical medicineRhythmInteraction networkPhysiology (medical)medicinesleepSettore MAT/07 - Fisica Matematica030304 developmental biologySlow-wave sleepOriginal Research0303 health scienceslcsh:QP1-981burstsMuscular systemSkeletal muscledynamic networksSleep in non-human animalsmedicine.anatomical_structuremuscle tonetime delay stabilitysynchronization030217 neurology & neurosurgeryFrontiers in Physiology
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Plasticity of brain wave network interactions and evolution across physiologic states

2015

Neural plasticity transcends a range of spatio-temporal scales and serves as the basis of various brain activities and physiologic functions. At the microscopic level, it enables the emergence of brain waves with complex temporal dynamics. At the macroscopic level, presence and dominance of specific brain waves is associated with important brain functions. The role of neural plasticity at different levels in generating distinct brain rhythms and how brain rhythms communicate with each other across brain areas to generate physiologic states and functions remains not understood. Here we perform an empirical exploration of neural plasticity at the level of brain wave network interactions repre…

AdultMaleNerve netCognitive NeuroscienceNeuroscience (miscellaneous)Sensory systemPlasticityCognitive neurosciencelcsh:RC321-571Young AdultCellular and Molecular NeuroscienceNeuroplasticitymedicineHumanslcsh:Neurosciences. Biological psychiatry. NeuropsychiatryOriginal ResearchSlow-wave sleepCerebral CortexNetwork physiologySleep StagesNeuronal PlasticityBrain WaveBrain wave interactions; Network physiology; Neural plasticity; Sleep; Time delay stability; Adult; Brain Waves; Cerebral Cortex; Female; Humans; Male; Nerve Net; Neuronal Plasticity; Sleep; Young Adult; Neuroscience (miscellaneous); Cellular and Molecular Neuroscience; Sensory Systems; Cognitive NeuroscienceNetwork dynamicsBrain WavesSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Sensory Systemsbrain wave interactionsmedicine.anatomical_structureBrain wave interactionFemaletime delay stabilityNerve NetSensory SystemPsychologySleepNeuroscienceHumanNeuroscienceneural plasticityFrontiers in Neural Circuits
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Universal spectral profile and dynamic evolution of muscle activation: A hallmark of muscle type and physiological state

2020

The skeletal muscle is an integrated multicomponent system with complex dynamics of continuous myoelectrical activation of various muscle types across time scales to facilitate muscle coordination among units and adaptation to physiological states. To understand the multiscale dynamics of neuromuscular activity, we investigated spectral characteristics of different muscle types across time scales and their evolution with physiological states. We hypothesized that each muscle type is characterized by a specific spectral profile, reflecting muscle composition and function, that remains invariant over time scales and is universal across subjects. Furthermore, we hypothesized that the myoelectr…

AgingElectromyographyPhysiologyChemistryMuscle typeMuscle activation030229 sport sciencesTime scalesAdaptation Physiological03 medical and health sciencesMuscle fibers0302 clinical medicineSpectral powerPhysiology (medical)Muscle FatigueBiophysicsHumansMaximal exerciseMuscle SkeletalExerciseSettore MAT/07 - Fisica Matematica030217 neurology & neurosurgeryFatigueMuscle ContractionResearch Article
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