|
Research article summary:
Brain electrical activity and subjective experience during altered states of consciousness: ganzfeld and hypnagogic states.
Abstract Extract: Manifestations of experimentally induced altered states of consciousness in the brains electrical activity as well as in subjective experience were explored via the hypnagogic state at sleep onset, and the state induced by exposure to an unstructured ... (Full abstract text below) Published 2002Nov
in Journal: Int J Psychophysiol
(Language : eng)
Full Pubmed Extract
This information was retrieved, real-time, on your behalf from the public area of the Pubmed website:
1. Int J Psychophysiol.
2002 Nov;46(2):123-46
Brain electrical activity and subjective experience during altered states of consciousness: ganzfeld and hypnagogic states.
Wackermann J, Pütz P, Büchi S, Strauch I, Lehmann D
Department of Empirical and Analytical Psychophysics, Institute for Frontier Areas of Psychology, i Br, Freiburg, Germany. jw@igpp.de
Manifestations of experimentally induced altered states of consciousness in the brain's electrical activity as well as in subjective experience were explored via the hypnagogic state at sleep onset, and the state induced by exposure to an unstructured perceptual field (ganzfeld). Twelve female paid volunteers participated in sessions involving sleep onset, ganzfeld, and eyes-closed relaxed waking, and were repeatedly prompted for recall of their momentary mentation, according to a predefined schedule. Nineteen channel EEG, two channels EOG and EMG were recorded simultaneously. The mentation reports were followed by the subjects' ratings of their experience on a number of ordinal scales. Two-hundred and forty-one mentation reports were collected. EEG epochs immediately preceding the mentation reports were FFT-analysed and the spectra compared between states. The ganzfeld EEG spectrum, showing no signs of decreased vigilance, was very similar to the EEG spectrum of waking states, even showed a minor acceleration of alpha activity. The subjective experience data were reduced to four principal components: Factor I represented the subjective vigilance dimension, as confirmed by correlations with EEG spectral indices. Only Factor IV, the 'absorption' dimension, differentiated between the ganzfeld state (more absorption) and other states. In waking states and in ganzfeld, the subjects estimated elapsed time periods significantly shorter than in states at sleep onset. The results did not support the assumption of a hypnagogic nature of the ganzfeld imagery. Dream-like imagery can occur in various global functional states of the brain; hypnagogic and ganzfeld-induced states should be conceived as special cases of a broader class of 'hypnagoid' phenomena.
PMID : 12433389 [PubMed - Indexed for MEDLINE]
This information is obtained from the National Library of Medicine (NLM). Abstract text and other information may be subject to copyright. Type "NLM copyright" into Google for more information.
Full Author Information
| First Name | LastName | Initials |
| Jiri | Wackermann | J |
| Peter | Pütz | P |
| Simone | Büchi | S |
| Inge | Strauch | I |
| Dietrich | Lehmann | D |
Affiliation: Department of Empirical and Analytical Psychophysics, Institute for Frontier Areas of Psychology, i Br, Freiburg, Germany. jw@igpp.de
3rd Party provider links
Click the links below to go to related 3rd party information:
MESH categories and related page links
This article was linked to the MESH categories shown on the left below. The links on the right are related Memletics pages.
Category links from this article:- Adult
- Analysis of Variance
- Brain - physiology
- Electroencephalography
- Electromyography
- Electrooculography
- Evoked Potentials - physiology
- Female
- Humans
- Perception
- Relaxation - physiology
- Sleep Stages - physiology
- Time Factors
- Visual Fields - physiology
- Wakefulness - physiology
| | Related Memletics topics: |
Links for this articleFor links to places where you can get the full text of this article see links. Note there may be a subscription or fee required for access to the full text. New! Using similar technology to this site, we have launched find-health-articles.com, targeting over 1 million health research article abstracts. Related ArticlesHere are some articles related to this one (by title keywords): Keywords in this article:absorption, acceleration, according, activity, alpha, altered, analysed, assumption, brain, broader, cases, channel, channels, class, closed, collected, compared, components, conceived, confirmed, consciousness, correlations, data, decreased, differentiated, dimension, dream, eeg, elapsed, electrical, emg, eog, epochs, estimated, even, experience, experimentally, explored, exposure, eyes, factor, female, fft, field, followed, forty, four, functional, ganzfeld, global, hundred, hypnagogic, hypnagoid, imagery, immediately, indices, induced, involving, like, manifestations, mentation, minor, momentary, more, nature, nineteen, not, number, occur, one, only, onset, ordinal, other, paid, participated, perceptual, periods, preceding, predefined, principal, prompted, ratings, recall, recorded, reduced, relaxed, repeatedly, reports, represented, results, scales, schedule, sessions, shorter, showing, signs, similar, simultaneously, sleep, special, spectra, spectral, spectrum, states, subjective, subjects, support, time, twelve, two, unstructured, via, vigilance, volunteers, waking, well
|