Brain wave frequency

From wakefulness to deep sleep, there is a progression of EEG activity, slowing from beta wave activity (about 18 Hz) to theta-delta wave activity (3.5 to 8 Hz). Figure 17.43 shows the appearances of the major brain wave frequencies. The delta waves occur in deep sleep or coma. Theta waves are... 

Keywords— Brain wave frequency, MEG, Physical agent, Miswak (Kayu Sugi), Neurorehabilitation. 

The psychology of brain waves is a tempting field, but with much contradiction. Any form of psychological correlation is opposed by the psychoanalysts. They question all correlations between brain wave frequency and mental effort. Fast frequencies are said to be common in schizophrenics. 

These results led us to analyze the relationship between carrier-wave frequency and power density. We developed a mathematical model (6) which takes into account the changes in complex permittivity of brain tissue with frequency. This model predicted that a given electric-field intensity within a brain-tissue sample occurred at different exposure levels for 50-, 147-, and 450-MHz radiation. Using the calculated electric-field intensities in the sample as the independent variable, the model demonstrated that the RF-induced calcium-ion efflux results at one carrier frequency corresponded to those at the other frequencies for both positive and negative findings. In this paper, we present two additional experiments using 147-MHz radiation which further test both negative and positive predictions of this model. 

Values of P. used in previously reported experiments on calcium- ion efflux from chick-brain samples at carrier-wave frequencies of 50, 147, and 450 MHz. 

Specific values of P. used in previously reported experiments on calcium-ion efflux from chick-brain samples are listed in Table I under the carrier wave frequency used in the experiment (3,4,1 ). In addition, values of P. which result in the same E in the sample have been calculated for the other carrier frequencies using Equations (3) and (4). For example, 3.64 mW/cm2 at 50 MHz, 0.83 mW/cm2 at 147 MHz, and... 

Keeping the average electric field intensity the same within a spherical model of chick-brain in buffer solution at different incident carrier wave frequencies requires that incident power density be changed with frequency to compensate for the change in complex permittivity and wavelength with frequency. The resulting Equations (3) and (A) relate corresponding values of P. at carrier frequencies of 50, 1A7, and A50 MHz. 1... 

Other evidence corroborates these data, and confirms that vomeropherin stimulation of the VNO can affect autonomic functions [249e]. This study also tested various chemicals to show that they depolarized the VNO and only the VNO. It also found that such stimulation of the VNO eould alter such autonomic variables as cardiac frequency, respiratory frequency, and electrodermal activity, and supports the idea that vomeropherins can alter the ratio of alpha to beta brain waves in the cortex. 

They had found that they could more easily catalog Herman s memories and distinguish real events from the rest of the noise in his brain by first having Herman produce mu waves between 8 and 13 Hz. (This took Herman a few days of practice, but he soon learned to generate mu waves whenever he wanted to.) These brain waves arose at a few frequencies within the alpha waves produced by a wakeful but relaxed brain. Malcolm told Herman that mu waves were the resting rhythms generated by neurons in the sensorimotor cortex, a diffuse region of the brain that lay on top of the head, between the ears. 

These properties give a peculiar look to G as shown in Fig. 5.5. Physically, this seems to reflect the fact that the oscillators whose natural frequencies are close to cuo are pulled perfectly into the central frequency to form a sharp peak, while this results in a remarkable population decrease around this peak. This is the very feature that caught N. Wiener s attention (1965), in connection with the spectrum of the a rhythm of the human brain waves. 

Authors EEG/EOG analysis Sample frequency Filter Analyzed channels Rhythm brain waves... 

Clapp, N.E. Hively, L.M. 1997. Method and apparatus for extraction of low-frequency artifacts from brain waves for alertness detection. Google Patents. 

The spontaneous electrical activity of the brain can be measured by electroencephalography (EEG), a technique that has been widely employed to study neurotoxic effects of chemicals both in humans and in experimental animals. EEG waves represent summated synaptic potentials generated by the pyramidal cells of the cerebral cortex (Misra 1992). These potentials are the responses of cortical cells to rhythmical changes arising from thalamic nuclei. The signals recorded can be separated into frequency bands—faster waves exceeding 13 Hz, and slower ones below 4 Hz. 

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