Neuroscientists' efforts to better understand the underlying processes of human consciousness are growing in a variety of multidisciplinary approaches. Relevant within these are the studies aimed at exploring the physiological substratum of the propagation and reduction of cerebral-namely, corticocortical-communication flows. However, the preferential direction of the information flow between b...

The present study attempt to investigate the changes of the electroencephalogram (EEG) rhythms due to physical fatigue. Three different methods to enhance EEG signals have been applied. Aside from the Referential method, the Common Average Reference method as well as the Current Source Density method has been applied to the raw data prior to processing. Ten subjects participated in this study. ...

Background: In relaxed adults, staying in quiet wakefulness at eyes closed is related to the so-called resting state electroencephalographic (rsEEG) rhythms, showing highest amplitude posterior areas alpha frequencies (8–13 Hz). Objective: Here we tested hypothesis that age may affect rsEEG (8–12 Hz) rhythms recorded normal elderly (Nold) seniors and patients with mild cognitive impairment due ...

Drosophila melanogaster is a common model used to study circadian rhythms in behavior and circadian clocks. However, numerous circadian rhythms have also been detected in non-clock neurons, especially in the first optic neuropil (lamina) of the fly's visual system. Such rhythms have been observed in the number of synapses and in the structure of interneurons, which exhibit changes in size and s...

Despite the several-thousand-fold increase of brain volume during the course of mammalian evolution, the hierarchy of brain oscillations remains remarkably preserved, allowing for multiple-time-scale communication within and across neuronal networks at approximately the same speed, irrespective of brain size. Deployment of large-diameter axons of long-range neurons could be a key factor in the ...

Recordings of ongoing neural activity with EEG and MEG exhibit oscillations of specific frequencies over a non-oscillatory background. The oscillations appear in the power spectrum as a collection of frequency bands that are evenly spaced on a logarithmic scale, thereby preventing mutual entrainment and cross-talk. Over the last few years, experimental, computational and theoretical studies hav...

It is a major source of contention in brain dynamics as to whether the electrical rhythms of the brain show signs of chaos. Here we discuss evidence for the existence of chaos in a theory of brain electrical activity and provide unique depictions of the dynamics of this model. r 2002 Elsevier Science Ltd. All rights reserved.

Humans tend to spontaneously align their movements in response to visual (e.g., swinging pendulum) and auditory rhythms (e.g., hearing music while walking). Particularly in the case of the response to auditory rhythms, neuroscientific research has indicated that motor resources are also recruited while perceiving an auditory rhythm (or regular pulse), suggesting a tight link between the auditor...

Total glucocorticoid hormone levels in plasma of various species, including humans, follow a circadian rhythm that is made up from an underlying series of hormone pulses. In blood most of the glucocorticoid is bound to corticosteroid-binding globulin and albumin, resulting in low levels of free hormone. Although only the free fraction is biologically active, surprisingly little is known about t...

The normal system of ordinary differential equations, whose right-hand sides are the ratios linear and nonlinear positive functions, is considered. A feature these that some their denominators can take on arbitrarily small nonzero values. (Thus, modules corresponding derivatives large value.) In sequel, constructed equations used to model strongly oscillating processes (for example, determined ...