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Correlations between different EEG patterns and serum concentrations during Phenothiazine therapy
FREE COMMUNICATIONS IN EEG 4. Extinction of EEG seizure discharges by an increase of pCO 2 is associated with a moderate hyperpolarization of the motoneurones. Simultaneously the evoked postsynaptic potentials disappear. The induced response patterns of spinal motoneurones during cerebral convulsive discharges resemble those observed in the immediate area of active foci.
93.
Correlations between different EEG patterns and serum concentrations during Phenothiazinc t h e r a p y . - H . Helmchen, and S. Kanowski (Berlin, W. Germany).
Changes in background activity and appearances of paroxysmal rhythmic and dysrhythmic discharges during therapy with neuroleptic drugs are well known. These changes have been followed in 282 EEGs taken from 50 patients over a 30-day period while on a constant dose of Perazine. The frequencies of the alpha dominant type EEG, the small amplitude EEG, regular 7 to 8 c/s activity and irregular activity increased significantly during the course of Perazine therapy. The same was true for continuous and paroxysmal dysrhythmias and even focal disturbances appeared more often under this therapy. Left-sided foci were more c o m m o n than those appearing on the right. Continuous and grouped abnormal m o n o r h y t h m i c activity appeared mainly under therapy. Generalized slowed and irregular activity of pathological amounts was not seen. Hypersynchronous high voltage discharges developed in only two patients while under therapy. The serum concentration of Perazine was determined prior to the EEG being taken. Correlations have been made using a special computer program between the EEG changes under Perazine therapy and the averaged and special serum concentrations of the Perazine.
94.
Memory and vigilance: spectral EEG analysis during learning in h u m a n s . - M . Koukkou, J.
M. Madey and C. L. Yeager (San Francisco, Calif., U.S.A.). Behavioral experiments indicate that learning is facilitated with increased vigilance. The level of vigilance can be assessed using the spectral distribution of wave frequencies in the EEG. We tested the hypothesis that the degree of vigilance after presentation of memory material determines the quality of memory storage in normal humans. Short, meaningful sentences were presented to sleeping subjects via a loudspeaker. These presentations resulted in brief periods of increased vigilance. Retention of the sentences was tested after the experiment; the results were classified as spontaneous recall, or possibility to recognize, or "flo memory".
687
The parieto-occipital EEGs recorded during 90 sec after the presentations were subjected to a spectral analysis (period analysis) in 5-sec intervals. The spectra of corresponding intervals for the same class of recall were averaged over all subjects. The average EEG spectra during 5 to 15 sec after the presentation showed a wakefulness-type frequency distribution for the cases of spontaneous recall and recognition, and a sleep-type distribution for the cases of "no m e m o r y " . The EEG spectrum for the cases of recognition showed an increase of slower frequencies and a reduction of higher frequencies at 25 to 35 sec after the presentation. With further increase in time after the presentation, the spectrum for the cases of recognition, and later the spectrum for the cases of spontaneous recall approached the sleep distribution. In addition, EEG spectra obtained during learning of new sentences were compared with spectra during relearning of sentences which were familiar to the subjects. Within the same class of recall, distinctly higher levels of vigilance were associated with learning of unfamiliar material than with relearning of familiar material. Our results demonstrate a systematic relation between the level of vigilance (objectively assessed by computer analysis of the EEG) during learning and the quality of the memory storage.
95.
Bizarre EEG of striate cortex in blind squirrel monkeys.-H. Sakakura and R. H. Doty (Osaka, Japan and Rochester, N.Y., U.S.A.).
In normal, unanesthetized squirrel monkeys oscilloscopic recordings from electrodes with 1 mm tip separation in the striate cortex often show 40-60/sec oscillations at 100-300 /.tV, for several seconds when room lights are turned on; and similar oscillations may occur for a briefer period with onset of darkness. Such oscillations, however, are often absent or may be suddenly curtailed by eye movements or change of attention. There is no prominent alpha rhythm. Responses of striate cortex to electrical pulses to optic radiation are strongly influenced by light versus darkness or by state of alertness (e.g., wakefulness versus slow wave sleep). After bilateral enucleation of the eyes, the EEG of striate cortex becomes flat, punctuated by sporadic spikes, at 200-300 /aV, lasting 100 msec. Many but not all of these spikes are correlated with eye movements (as indicated by the EMG of the eye muscles after enucleation). These spikes are sometimes followed by a burst of large amplitude slow waves. After several weeks the slow waves occur more often, occupy more of the record and sometimes have faster activity superimposed on them, but continue to be interrupted by flat periods lasting about 1 sec. The
93.
Correlations between different EEG patterns and serum concentrations during Phenothiazinc t h e r a p y . - H . Helmchen, and S. Kanowski (Berlin, W. Germany).
Changes in background activity and appearances of paroxysmal rhythmic and dysrhythmic discharges during therapy with neuroleptic drugs are well known. These changes have been followed in 282 EEGs taken from 50 patients over a 30-day period while on a constant dose of Perazine. The frequencies of the alpha dominant type EEG, the small amplitude EEG, regular 7 to 8 c/s activity and irregular activity increased significantly during the course of Perazine therapy. The same was true for continuous and paroxysmal dysrhythmias and even focal disturbances appeared more often under this therapy. Left-sided foci were more c o m m o n than those appearing on the right. Continuous and grouped abnormal m o n o r h y t h m i c activity appeared mainly under therapy. Generalized slowed and irregular activity of pathological amounts was not seen. Hypersynchronous high voltage discharges developed in only two patients while under therapy. The serum concentration of Perazine was determined prior to the EEG being taken. Correlations have been made using a special computer program between the EEG changes under Perazine therapy and the averaged and special serum concentrations of the Perazine.
94.
Memory and vigilance: spectral EEG analysis during learning in h u m a n s . - M . Koukkou, J.
M. Madey and C. L. Yeager (San Francisco, Calif., U.S.A.). Behavioral experiments indicate that learning is facilitated with increased vigilance. The level of vigilance can be assessed using the spectral distribution of wave frequencies in the EEG. We tested the hypothesis that the degree of vigilance after presentation of memory material determines the quality of memory storage in normal humans. Short, meaningful sentences were presented to sleeping subjects via a loudspeaker. These presentations resulted in brief periods of increased vigilance. Retention of the sentences was tested after the experiment; the results were classified as spontaneous recall, or possibility to recognize, or "flo memory".
687
The parieto-occipital EEGs recorded during 90 sec after the presentations were subjected to a spectral analysis (period analysis) in 5-sec intervals. The spectra of corresponding intervals for the same class of recall were averaged over all subjects. The average EEG spectra during 5 to 15 sec after the presentation showed a wakefulness-type frequency distribution for the cases of spontaneous recall and recognition, and a sleep-type distribution for the cases of "no m e m o r y " . The EEG spectrum for the cases of recognition showed an increase of slower frequencies and a reduction of higher frequencies at 25 to 35 sec after the presentation. With further increase in time after the presentation, the spectrum for the cases of recognition, and later the spectrum for the cases of spontaneous recall approached the sleep distribution. In addition, EEG spectra obtained during learning of new sentences were compared with spectra during relearning of sentences which were familiar to the subjects. Within the same class of recall, distinctly higher levels of vigilance were associated with learning of unfamiliar material than with relearning of familiar material. Our results demonstrate a systematic relation between the level of vigilance (objectively assessed by computer analysis of the EEG) during learning and the quality of the memory storage.
95.
Bizarre EEG of striate cortex in blind squirrel monkeys.-H. Sakakura and R. H. Doty (Osaka, Japan and Rochester, N.Y., U.S.A.).
In normal, unanesthetized squirrel monkeys oscilloscopic recordings from electrodes with 1 mm tip separation in the striate cortex often show 40-60/sec oscillations at 100-300 /.tV, for several seconds when room lights are turned on; and similar oscillations may occur for a briefer period with onset of darkness. Such oscillations, however, are often absent or may be suddenly curtailed by eye movements or change of attention. There is no prominent alpha rhythm. Responses of striate cortex to electrical pulses to optic radiation are strongly influenced by light versus darkness or by state of alertness (e.g., wakefulness versus slow wave sleep). After bilateral enucleation of the eyes, the EEG of striate cortex becomes flat, punctuated by sporadic spikes, at 200-300 /aV, lasting 100 msec. Many but not all of these spikes are correlated with eye movements (as indicated by the EMG of the eye muscles after enucleation). These spikes are sometimes followed by a burst of large amplitude slow waves. After several weeks the slow waves occur more often, occupy more of the record and sometimes have faster activity superimposed on them, but continue to be interrupted by flat periods lasting about 1 sec. The