PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Brain waves”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1975

[Effect of intermittent noise on the function of concentration maintenance (TAF) and the brain waves (author's transl)].

The effect of three different kinds of noise, having equal physical energy but different psychological load, was examined by the TAF-test and the brain waves. Thirty nine healthy male subjects aging from 19 to 34 were exposed to white noise of 80 dB (C) under the following three conditions: (1) continuous noise for ten minutes, (2) regular intermittent noise, consisted of one-minute noise and one-minute rest, for 19 minutes, and (3) irregular intermittent noise, consisted of one-minute noise and irregular rest period, for 19 minutes. In each condition, the duration of noise-exposure totals ten minutes. Before, during and after the noise-exposure, the TAF-test was given to the 23 subjects out of 39, and the brain waves were recorded from the rest 16 subjects. The changes of TAF-L and alpha wave appearance were compared. The results obtained were as follows. 1. All three kinds of noise-exposure caused significant lowering of the function of concentration maintenance, especially in the latter half period of the noise administration. 2 Lowering of the function of concentration maintenance due to the irregular intermittent noise-exposure was greater than that due to the regular intermittent noise-exposure. 3. As to the continuous noise-exposure, appearance of the alpha wave decreased significantly in the 9th to 10th minute of noise administration and in the 1st min. after the exposure, while it increased in the 18th to 22nd min. after the exposure. 4. Exposure to the regular intermittent noise resulted in a significant decrease of the alpha wave appearance at the latter half of the noise administration, which continued after the exposure. 5. Exposure to the irregular intermittent noise caused a significant decrease of the alpha wave appearance after the middle period of noise administration. 6. Comparing the regular intermittent noise and irregular one, the latter brought about stronger alpha-blocking during the noise administration, but earlier restoration after the exposure. These results indicate that the influences of noise as a stressor differ not only by the amount of its physical energy but also by the condition of its generation, and that the differences of on-off effect on the brain activities based on regular or irregular intermittent noise were grasped by the changes of the function of concentration maintenance and the alpha wave appearance.

Adult↗
PubMed2006

A theoretical basis for standing and traveling brain waves measured with human EEG with implications for an integrated consciousness.

OBJECTIVE: We propose a theoretical framework for EEG and evoked potential studies based on the single postulate that these data are composed of a combination of waves (as this term is used in the physical sciences) and thalamocortical network activity. METHODS: Using known properties of traveling and standing waves, independent of any neocortical dynamic theory, our simple postulate leads to experimental predictions, several of which have now been verified. A mathematical-physiological theory of "brain waves" based on known (but highly idealized) properties of cortical synaptic action and corticocortical fibers is used to support the framework. RESULTS: Brain waves are predicted with links between temporal frequencies and the spatial distributions of synaptic activity. Such dispersion relations, which essentially define more general phenomena as waves, are shown to restrict the spatial-temporal dynamics of synaptic action with many experimental EEG consequences. CONCLUSIONS: The proposed framework accounts for several salient features of spontaneous EEG and evoked potentials. SIGNIFICANCE: We conjecture that wave-like behavior of synaptic action may facilitate interactions between remote cell assemblies, providing an important mechanism for the functional integration underlying conscious experience.

Algorithms↗
PubMed1994

Brain waves associated with musical incongruities differ for musicians and non-musicians.

Musicians and non-musicians were presented with short musical phrases that were either selected from the classical musical repertoire or composed for the experiment. The phrases terminated either in a congruous or a 'harmonically', 'melodically', or 'rhythmically' incongruous note. The brain waves produced by the end-notes differed greatly between musicians and non-musicians, and as a function of the subject's familiarity with the melodies and the type of incongruity. The timing of these brain waves revealed that musicians are faster than non-musicians in detecting incongruities. This study provides further neurophysiological evidence concerning the mechanisms underlying music perception and the differences between musical and linguistic processing.

Brain↗
PubMed1993

Blinking, alpha brain waves and smoking in schizophrenia.

Blink rates (BR) and alpha brain waves were studied in 13 schizophrenic and 13 healthy smokers under conditions of smoking deprivation as well as smoking saturation and under different task conditions of smooth pursuit eye movements. Task conditions significantly changed BR and alpha power; smoking enhanced BR and alpha frequency, the latter effect being especially pronounced in schizophrenics for F3-F4 leadings. Concerning BR, groups differed significantly as long as smoking quantity was not statistically controlled. BR, alpha power and smoking quantity were consistently correlated above chance levels. Results are discussed with respect to the blink alpha neurocircuit model.

Adult↗
PubMed2000

Behavioral and brain wave evidence for automatic processing of orthographically regular letter strings.

Evidence for the automatic processing of nonword letter strings was sought in subjects who performed two different perceptual tasks. Twelve subjects detected valid words. Twelve other subjects detected Gestalt patterns that contained no letters. The targets and two types of nonword letter strings were interspersed in a stream of nonletter images. Behavioral data showed significant effects of orthographic regularity of letter strings in the group that detected words, but not in the group that detected Gestalt patterns. Brain-wave responses showed the effect of orthographic regularity in both groups. The responses were significantly larger for regular than for irregular strings. This showed that brain waves can be used to study the operation of reading processes in subjects who are performing a task that does not require reading ability.

Adult↗
PubMed1988

P3-like brain waves in normal monkeys and in monkeys with medial temporal lesions.

The human brain produces a characteristic electrical response to relevant events that occur unexpectedly. Recent reports have suggested that a prominent part of this event-related brain potential--the P3 wave--may be related to memory functions and may arise from activity within the medial temporal lobe, especially the hippocampus. The latter idea was tested by means of epidural recordings of brain waves in monkeys. Responses to deviant auditory stimuli bore a close resemblance to P3 waves recorded from human subjects under comparable conditions. Monkeys with bilateral lesions of the medial temporal lobe still produced P3-like brain waves, which indicates that medial temporal brain structures are not critical for their generation.

Acoustic Stimulation↗
PubMed1962

Beta brain waves as an index of alertness.

Reaction times of human subjects are reliably shorter when the signal to respond is given during spontaneous low voltage, fast (beta) brain waves than they are when the signal is given during spontaneous alpha waves. The mean difference of 12 milliseconds is, however, trivial in comparison to the advantage to be expected from forewarning.

Attention↗
PubMed2000

Brain-wave representation of words by superposition of a few sine waves.

Data from three previous experiments were analyzed to test the hypothesis that brain waves of spoken or written words can be represented by the superposition of a few sine waves. First, we averaged the data over trials and a set of subjects, and, in one case, over experimental conditions as well. Next we applied a Fourier transform to the averaged data and selected those frequencies with high energy, in no case more than nine in number. The superpositions of these selected sine waves were taken as prototypes. The averaged unfiltered data were the test samples. The prototypes were used to classify the test samples according to a least-squares criterion of fit. The results were seven of seven correct classifications for the first experiment using only three frequencies, six of eight for the second experiment using nine frequencies, and eight of eight for the third experiment using five frequencies.

Acoustic Stimulation↗