Results 241 to 250 of about 187,527 (276)

Origin of the Alpha Rhythm

Nature, 1970
The 8–12 Hz rhythmical waveform that can be recorded from the scalp of most human subjects when their eyes are closed does not originate in brain tissue. It is generated by physiological tremor in the extra-ocular muscles modulating the field set up by the standing potential of the eye.
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Decomposition of posterior alpha rhythm

IEEE Transactions on Biomedical Engineering, 2000
The classical posterior alpha rhythm has been decomposed into regular and irregular components using orthogonal transformation. A periodicity generator is considered, which has three characteristic control parameters: the periodicity, the amplitudes or scaling factors and the pattern associated with successive periodic segments.
Joydeep Bhattacharya, Partha Pratim Kanjilal, Haque H. Nizamie   +2 more
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The cortical source of the alpha rhythm

Neuroscience Letters, 1977
Abstract The question of the intracortical sources of the alpha activity of the EEG has been investigated in dogs, using intracortical electrodes placed along a direction perpendicular to the cortical surface. Alpha rhythms have been quantified using spectral analysis, namely the phase relationships between alpha activities recorded between several ...
F H, Lopes Da Silva, W, Storm Van Leeuwen   +1 more
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The cerebral origin of the alpha rhythm

Electroencephalography and Clinical Neurophysiology, 1988
The EEG alpha rhythm was recorded from 8 isolated canine brains in the absence of orbital contents, drug effect, or pulsatile cerebral blood flow. Abrupt shift to hypoxic perfusion, with maintenance of other perfusion variables, resulted in a loss of alpha coincident with a fall in CMRO2 and rise in oxygen deficit. It is concluded that the alpha rhythm
K, Hogan, J, Fitzpatrick
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OCULOMOTOR ACTIVITY AND THE ALPHA RHYTHM

Perceptual and Motor Skills, 1990
From the beginning of clinical use of the EEG until now a close connection with oculomotor activity was assumed and empirically proven. After giving a sketch of the historical development, the issue is extended to the question of a connection between task-related alpha asymmetries and oculomotor activity.
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Alpha rhythm and hypofrontality in schizophrenia

Acta Psychiatrica Scandinavica, 2008
Objective:  To reveal the EEG correlates of resting hypofrontality in schizophrenia (SZ).Method:  We analyzed the whole‐head EEG topography in 14 patients compared to 14 matched controls by applying a new parameterization of the multichannel EEG. We used a combination of power measures tuned for regional surface mapping with power measures that allow ...
Knyazeva MG, Jalili M, Meuli R, Hasler M, De Feo O, Do KQ   +5 more
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Propofol-Induced Alpha Rhythm

Neuropsychobiology, 2004
The electroencephalographic effects of two intravenous sedative/hypnotic drugs, propofol and thiopental, were studied at three stable blood concentrations in 52 normal healthy volunteers. The higher concentration resulted in unresponsiveness (lack of response to auditory/tactile stimuli) in all subjects. This report describes the strong frontal-central
Vladimir A, Feshchenko, Robert A, Veselis, Ruth A, Reinsel   +2 more
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Alpha Rhythm and Alpha-Like Activity in Coma

Clinical Electroencephalography, 1984
A normal waking EEG was obtained on a 22 year old man four days prior to cardiopulmonary arrest. Three days after resuscitation the EEG showed the pattern of alpha-like activity while the patient remained in deep coma. Since the EEGs were recorded by the same technician using the same 16 channel electroencephalograph and montages, it is possible to ...
P C, Fung, R P, Tucker
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Alpha Rhythm and the Pineal Gland

International Journal of Neuroscience, 1992
Alpha rhythm is classically described as a bilateral posterior rhythm of substantially constant frequency in the range of 8-13 Hz which is enhanced by mental relaxation and blocked by attention. Since the full expression of alpha rhythm has been shown to occur coincident with puberty, it is possible that the establishment of alpha rhythm is subject to ...
exaly   +3 more sources

ALPHA RHYTHM

The Lancet, 1970
J.M. Pereda, P.M. Jeavons
  +6 more sources