Personality and frontal midline theta activity

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P12 (N13) were normal, but N16 was absent. N18 (N20) was absent only with thalamic or cerebral hemisphere lesions. These findings suggest that the far-field potentials N9 to Nil are generated in the cervical posterior column and N16 in the mid-brain or thalamus. C-20.04 EFFECTS OF CENTRAL ACTING DRUGS ON FRONTAL MIDLINE THETA ACTIVITY. M. Tanaka, Y. Mizuki, 0. Takii, H. Nishijima, H. Mukasa, H. Isozaki and K. Inanaga (Kurume, Japan) The frontal midline theta activity which appears during performance of mental tasks has beendesignated as Fmg. Twelve male university studentswho had failed to show any appearance of Fmeinthree consecutive days were given placebo and two centrally acting druqs, i.e.,an anxiolytic, diazepam 5 mg, and a stimulant, methylphenidate lOmg, in a double-blind,cross-over design. Filling out the anxiety scaleofspielberger, State TraitAnxiety Inventory(STAI), they recorded EEGs monopolarly beforeand during performance of an arithmetic addition(Uchida-Kraepelin) test. The tests were done twice, before and 1.5 h after thedruq administration. Fmg appeared in 4,6 and 2 sub-jects out of 12 subjects on administration of placebo, diazepam and methylphenidate, respectively. Both placebo and diazepam decreased the STAI scores;however, methylphenidateincreased them slightly.Placebo and methylphenidate increasedtheamounts ofthetasksperformed butdiaze pam decreased themslightly. These results suggest that theappearanceofFm0 is influenced by centrally actingdrugs andFmgcan appearafterdrugadministration eveninthose whohavenever shown it involved and that the relief fromanxietymightbe in the appearance of Fmg. A-1.09 PREDICTION OF CLINICAL EFFECTS OF SOME ANXIOLYTIC AND HYPNOTIC DRUGS BY AVERAGED PHOTOPALPEBRAL REFLEX. M. Tanaka, Y. Hizuki, H. Isozaki and K. Inanaga (Kurume, Japan) It is very important, yet a very difficult problem,to predict the clinical effects of newly introduced medicaments from pharmacological findinqs obtained in laboratory animals. For this purpose, it is necessary to develop a useful method to oredict the clinical efficacv of We' have predicted the clinical efthe drugs. fects of anxiolytic or hypnotic drugs by analyses of changes in the averaged photopalpebral reflex (PPR) in healthy adults. PPR is a record of summated reflex contractions of orbicularis oculi muscle to periodically applied photic stimuli and it changes very sensitively according to the arousal level. The experimental results indicated that the neak latencies were prolonged by lowerinq the arousal level, and shortened in a more aroused state. The latencics were prolonged by one anxiolytic, diazepam, and shortened by a central stimulant, methylphenidate, So we considered that PPE might be a use-

ful index for evaluation of drug effects on the arousal level. He have tested many anxiolytic and hypnotic drugs which belong to benzodiazepine derivatives in the PPR study. From these results, it is concluded that PPR is in many respects a good pharmacological index for investigation of these drug effects on the arousal level. D-3.06 PHYSIOLOGICAL STUDY OF THE AVERAGED PHOTOPALPEBRAL REFLEX IN MAN. H. Isozaki, M. Tanaka, Y. Mizuki and K. Inanaga (Kurume, Japan) It is well known that reflex contractions of the orbicularis oculi muscle can be induced by visual stimuli. This has been considered-to be a cortical reflex. The ootential chanaes of these muscle contractions to flashes given periodically can be summed and averaged, using a digital computer. k!e have called these averaged chanqes "photopaloebral reflex (PPR)". In the present study some basic matters were investigated to clarify the significance of PPR. The latencies of PPR were Drolonaed bv lowerina the arousal level and shortened by immersing the hand in ice water when a more aroused state was considered to be induced. The patterns of PPR recorded from electrodes placed on three different places of the upper lid were almost the same; however, among those of the lower lid, the nasal one was the most dominant compared with the more lateral ones. The amplitude increased and the latencies were shortened by increasing the brightness of the flashes. These results suggest that the PPR originates from contraction of orbicularis oculi muscle, especially pars palpebralis and pars orbitalis and that PPR is closelv related to the arousal level, so that PPR could be a useful tool for investigations of psychophysiology and psychopharmacology. C-19.02 PERSONALITY AND FRONTAL MIDLINE THETA ACTIVITY. K. Inanaga, 0. Takii, H. Nishijima, H. Mukasa, Y. Mizuki and M. Tanaka (Kurume, Japan) We have already reported on the frontal midline theta activity (Fm0) whose appearance shows inIn the present study, we dividual differences. investigated the relatiohship between the appearance of FmG)and the subject's personality to clarify individual differences. Thirty male university students were requested to perform continuous arithmetic addition (Uchida-Kraepelin test) for 15 min. EEGs were recorded monopolarly from disc electrodes placed on Fz and Cz during the test. They were requested to fill out Maudsley Personality Inventory (MPI) and Taylor's Manifest Anxiety Scale (MAS). FmB appeared in 22 out of 30 subjects; however, no relationship was observed between the amount of the performed tasks and the appearance of FmB.

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Those who showed low scores on the anxiety scale of MAS, hiah scores on the extrovert scale of MPI, and low scores on the neurotic scale of MPI were apt to show larqer amounts of Fran. On the contrary, those who showed high scores on the anxiety scale of HAS, low scores in the extrovert scale of MPI and hiqh scores on the neurotic scale of MPI were apt to show small amounts of FmB or no appearance of Fm6. From these results, the appearance of Fmn was suggested to be closely related to the subject's personality. C-20.01 PERIODIC THETA ACTIVITY. jima, H. Mukasa, (Kurume, Japan)

APPEARANCE OF FRONTAL MIDLINE Y. Mizuki, 0. Takii, H. NishiM. Tanaka and K. Inanaga

The distinct theta rhythm in the frontal midline area during performance of a mental task has In the present study, peribeen called Fm6. odicity in the appearance of FmB was investiThirty male university students were gated. requested to perform the Uchida-Kraepelin test (a test of continuous arithmetic addition) for EEGs were recorded monopolarly from 5 min. disc electrodes placed on Fz and Cz during the A 5 min distribution diagram whole procedure. of appearance of Fmf3 was defined accordinq to Fmn appeared in 19 out of 30 subour criteria. The total appearance time of Fm0 in each jects. subject showed no correlation either with the amount ofthe performed taskorthe numberof errors.. In subjects who showed a relatively small amount of Fme, it tended to appear mainly-at 6 points about 20. in the 5 min distribution diaqram; 60, 100, 240, and 290 set after the beginnino In contrast, Frnb was almost of calculation. uniformly distributed in those who showed a larger amount of Fme. These results suggest that appearance of FmB shows individual differences and there might exist some periodicity of an attention mechanism in certain subjects. C-20.03 THE INFLUENCE OF ALCOHOL Ok! THE APPEARANCE OF FRONTAL MIDLIF!E THETA ACTIVITY. H. Mukasa, 0. Takii, H. Mishijima, Y. Hizuki, II. Tanaka and K. Inanaga (Kurume, Japan) The distinct theta activity occurring in the frontal midline area during performance of a mental task has been called FmB. The appearance of Fme is considered to be closely related to the function of maintaining attention. The present study was undertaken to investigate effects of alcohol on the appearance of Fmn in 30 healthy male students. EEGs were recorded monopolarly from electrode Fz during a test of arithmetic addition (Uchida-Kraepelin test) for 5 min. They were tested twice before and 1 hr after taking alcohol, 1.5 ml of 43% whisk.y per kg of body weight. Alcohol concentrations in blood 1 hr after drinkino were determined. Fmn appeared in 11 out of 30-subjects before drink-

ing; however, the number of subjects with FmB appearance increased to 14 after drinking. The amount of FmB increased significantly after Mean + S.D. of alcohol concentrations drinking. in the blood was-52.8 + 10.5 mg/dl. No correlation was observed bebeen blood concentrations From these of alcohol and the amounts of Fmn. results, it is suggested that Fmn increases after drinking a small quantity of alcohol due to its tranquilizing effect. C-20.02 THE MIRROR DRAWING TEST AND FRONTAL HID0. Takii, H. Nishijima, LINE THETA ACTIVITY. H. Mukasa, Y. Mizuki, M. Tanaka and K. Inanaga (Kurume, Japan) He have already reported on the frontal midline theta activity (Fme) which is supposed to be related to the function of maintaining attenIn the present study, 30 male university tion. students were asked to perform the mirror drawing test (MDT) for 5 min continuously, where the subjects trace a star-shaped figure by EEGs were recorded watching the mirror image. monopolarly from disc electrodes placed on Fz and Cz during the test. Fmn which lasted for more than 1 set appeared in 15 out of 30 subNo difference was objects during the MDT. served either in the performance or in the number of errors betweeen the Fmn appearance group The figure of and the non-appearance group. the star in the MDT was divided equally into 5 blocks and the time when FmB appeared in each block was calculated as a value per 5 min. Fmn appeared most at the block where most time was spent, i.e., at the most difficult block. From these results it is suggested that the appearance of Fme is closely related to the function of maintaining attention. C-20.05 BIOFEEDBACK OF FROF!TAL THETA BURSTS. ld. Yasumo, T. Tsujimoto and Y. Yamaquchi (Osaka, Japan) During mental work some subjects ,show 6-7 c/set theta bursts in frontal midline EEGs (Fm-theta). In a previous report it was stated that the appearance of the Fm-theta could be recognized and controlled by the subject himself after biofeedback training. Long term biofeedback training wastried in this experiment. The training was performed intermittently for up to about ten months. The EEGs were recorded during continuous addition and the subject was informed when Fm-theta After some training procedures the appeared. subject could guess rightly the appearance. A vague feeling corresponding to the appearance existed, but was hard to put into words. In spite of this, the hit percentages became 80 100% at the end of the trainina. It is worthv of note that high amplitude Fm-theta was easier to guess right than low amplitude Fm-theta. Once the training was completed, memory of the Fm-