- Email: [email protected]
Winter conference on brain research
DUTCH SOCIETY
11. Quantitative electroencephalography: history, methods, applications. - - Z. Drohocki (Paris, France). (13-11968) According to Liberson (1937) and Hermann and Sager (1939) the statistical distribution of the amplitudes of the EEG waves obeys Maxwelrs law. Drohocki (1937) replaced measuring the amplitudes of the waves by integration of the EEG curve. He introduced (1938) the electronic integrator. Two methods are used now to quantitate and encode the E E G : (1) automatic integration; the product of the cerebral electrical activity and its fluctuations are converted into a chronogram; (2)statistical analysis, which gives for every period of the EEG a histogram of the amplitude distribution, an "amplitude spectrum". In both cases the production of cerebral electrical activity and its fluctuations are reproduced exactly by the amplitude spectrum and the chronogram and also by certain parameters (-~ : average amplitude of cerebral electrical activity; CV : 100 tr/~ : variation coefficient). These
303
parameters showed a large inter-regional and interindividual variability and an excellent intra-individual and intra-regional stability (constant level of the production of cerebral electrical activity). Physiological, pharmacological and pathological factors cause significant change in these parameters. The degree of change can be expressed excellently by comparison of the rather specific constant level. After the end of the disturbing influence, the production of cerebral electrical activity recovers invariably to the initial level. All the examined normal values excellently show the picture of a Gaussian distribution. The production of cerebral electrical activity is concentrated in a relatively narrow range around the average, which reproduces the constancy of the normal production of cerebral electrical activity. There are no significant individual deviations. Pathological cases (schizophrenia: Goldstein; cerebral tumours: Drohocki) show a significant change, on the contrary, so it is possible to distinguish the pathological cases with the help of these numerical criteria.
Electroenceph. clin. Neurophysiol., 1968, 25:300-303
ANNOUNCEMENT WINTER
CONFERENCE
The second annual Winter Conference on Brain Research will be held January 12-17, 1969 at the E1 Dorado Lodge, Snowmass-at Aspen, Colorado. The conference will be in plenary session format and its major theme will be Neural Substrates of Behavior. Daily sessions will be held late afternoons and evenings on subtopics related to the conference theme. A broad interdisciplinary approach is favored.
ON
BRAIN
RESEARCH
Outlines of presentations ( D e a d l i n e - November 1, 1968) must be sent to: Frederick D. Abraham, Neuropsychiatric Institute, University of California at Los Angeles, Los Angeles, Calif. 90024. For information on registration, room reservations ( D e a d l i n e - - October 1, 1968) and other general conference matters write to: John E. Swett, Ph.D., Department of Anatomy, University of Colorado Medical Center, Denver, Colo. 80220.
Electroenceph. clin. Neurophysiol., 1968, 25:303
11. Quantitative electroencephalography: history, methods, applications. - - Z. Drohocki (Paris, France). (13-11968) According to Liberson (1937) and Hermann and Sager (1939) the statistical distribution of the amplitudes of the EEG waves obeys Maxwelrs law. Drohocki (1937) replaced measuring the amplitudes of the waves by integration of the EEG curve. He introduced (1938) the electronic integrator. Two methods are used now to quantitate and encode the E E G : (1) automatic integration; the product of the cerebral electrical activity and its fluctuations are converted into a chronogram; (2)statistical analysis, which gives for every period of the EEG a histogram of the amplitude distribution, an "amplitude spectrum". In both cases the production of cerebral electrical activity and its fluctuations are reproduced exactly by the amplitude spectrum and the chronogram and also by certain parameters (-~ : average amplitude of cerebral electrical activity; CV : 100 tr/~ : variation coefficient). These
303
parameters showed a large inter-regional and interindividual variability and an excellent intra-individual and intra-regional stability (constant level of the production of cerebral electrical activity). Physiological, pharmacological and pathological factors cause significant change in these parameters. The degree of change can be expressed excellently by comparison of the rather specific constant level. After the end of the disturbing influence, the production of cerebral electrical activity recovers invariably to the initial level. All the examined normal values excellently show the picture of a Gaussian distribution. The production of cerebral electrical activity is concentrated in a relatively narrow range around the average, which reproduces the constancy of the normal production of cerebral electrical activity. There are no significant individual deviations. Pathological cases (schizophrenia: Goldstein; cerebral tumours: Drohocki) show a significant change, on the contrary, so it is possible to distinguish the pathological cases with the help of these numerical criteria.
Electroenceph. clin. Neurophysiol., 1968, 25:300-303
ANNOUNCEMENT WINTER
CONFERENCE
The second annual Winter Conference on Brain Research will be held January 12-17, 1969 at the E1 Dorado Lodge, Snowmass-at Aspen, Colorado. The conference will be in plenary session format and its major theme will be Neural Substrates of Behavior. Daily sessions will be held late afternoons and evenings on subtopics related to the conference theme. A broad interdisciplinary approach is favored.
ON
BRAIN
RESEARCH
Outlines of presentations ( D e a d l i n e - November 1, 1968) must be sent to: Frederick D. Abraham, Neuropsychiatric Institute, University of California at Los Angeles, Los Angeles, Calif. 90024. For information on registration, room reservations ( D e a d l i n e - - October 1, 1968) and other general conference matters write to: John E. Swett, Ph.D., Department of Anatomy, University of Colorado Medical Center, Denver, Colo. 80220.
Electroenceph. clin. Neurophysiol., 1968, 25:303