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Peak frequency of alpha activity shifts during mental tasks: Hemispheric differences
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of low voltage (l.OV, 0.5msec, 14-lHz, 2-5min). Based on these results, we developed a new stimulating apparatus ("SLEEPY") for the clinical use of electrosleep in man in cooperation with Homer Ion Institute (Tokyo). Clinical trials of "SLEEPY" (3.4V. 0.2msec. 14-1Hz. 30 min).were carried out on>60 insomniac subjects having no significant psychiatric, and organic For the assessement of efficacy, disturbances. a comparison between sleep questionnaires before and after use of "SLEEPY" at home was statistically made by sign test. The results showed sianificant effects (P
during the different stages of sleep under various conditions in 10 cats were determined by electrical stimulation through electrodes chronically implanted in the nucleus ventralis POStero-lateralis thalami (VPL). The arousal' thresholds durina PS were sianificantlv hiaher and more variable than those-found during Tight Especially, sleep and deep sleep in our study. the thresholds in the PS periods accompanied by eye movements were significantly higher than in PS periods without eye movements. In addition, when the PS period was divided into three parts (first. middle. last oeriod) accordina to the time course from PS onset, the threshold in the last period was significantly lower compared with the other two periods. Finally, we also investigated the changes in arousal thresholds accompanying Pavlovian alimentary conditioning when VPL stimulation was employed as conditioned stimulus. After the establishment of conditioning, the arousal thresholds in PS and light sleep periods were significantly lowered compared with those before conditioning. A-II.09 ANALYSIS OF THE DREAM CONTENTS IN JAPANESE COLLEGE STUDENTS BY REMP-AWAKENING TECHNIQLE. J. Matsumoto, T. Yamanaka and Y. Morita (Tokushima, Japan) The present study was performed on 39 japanese college students in Tokushima, aged from 19 to 21 years, using the REMP-awakening technique (collecting dreams by awakening the students during the period of REM sleep) which was established by Dement and others. The results consist of two parts, one at the lodging by observation (6 males, 12 females), the other at the laboratory by polygraphic recording (11 males, 10 females). All the procedures of dream reporting were recorded on magnetic tape and transcribed later. The contents of 297 dreams (220 in the lodging, 77 in the laboratory) were analysed and classified according to the Hall-Van de Castle scale (nature, material, character, activity, emotional element, etc.). The incidence of dreams was compared with that obtained from American college students by Hall and Van de Castle. Relationships between dream contents and polygraphic phenomena were also investigated. B-19.05 PEAK FREQUENCY OF ALPHA ACTIVITY SHIFTS DURING MENTAL TASKS: HEMISPHERIC DIFFERENCES. M. Osaka (Kyoto, Japan) Power spectral analyses were made of EEG recorded during arithmetic and visuo-spatial tasks: (1) simple addition, (2) complex addition, (3) visual imaqery, (4) mental rotation and (5) resting state.. Using 20 right-handed normal‘subjects, EEGs were recorded for 2 min from the right-and the left occipital and frontal sites. The results showed that (1) the peak
S54
frequencies of the power spectrum within the alpha band shifted markedly from 0.1 to about 0.8 Hz as the task changed from the resting state to the mental task. Furthermore, (2) the peak frequency significantly shifted toward a higher range in the left hemisphere during the complex addition task, whereas (3) the peak frequency markedly shifted toward a higher range in the right hemisphere during the mental rotation task. This suggests that the peak frequency of alpha activity is closely related to the difficulty of the mental task. Moreover, hemispheric differences found here indicate lateral asymmetry of brain function for verbal and nonverbal information processing.
location-of the maximum (plateau) stimulus intensity. In one type the rise and fall times were 5 msec, and the plateau duration was 35m sec. In other two types, the rise and fall times were, respectively, 5 msec and 30 msec or the reverse, and their plateau durations were 10 msec. The amplitude of the Pl-Nl component in in the evoked potential seems to correspond with the sound energy simply integrated within 45 mset duration. BY contrast, the amolitude of the Nl-P2 component-was not greatly affected by the temporal integration of sound energy, and its amplitude was significantly larger when the maximum intensity appeared 30 msec after the onset than when it appeared immediately after the onset. This result supports the above hypothesis.
C-5.04 OBSERVATIONS ON SPINAL CORD OR NERVE ROOT LESIONS THROUGH EVOKED SPINAL POTENTIAL MEASUREMENT. T. Kurokawa, N. Tsuyama, H. Tanaka, M. Kobayashi, H. Machida, K. Nakamura, T. Iizuka, Y. Hoshino and T. Imai (Tokyo, Japan)
D-9.01 THE INFLUENCE OF ATTENTION ON THE INTERFERENCE EFFECT OF MANUAL-VOCAL SIMULTANEOUS PERR. Nakamura and T. Chida (Narugo, FORMANCES. Japan)
A review was conducted of 283 patients who underwent evoked spinal action potential measurement. Spinal action potentials were evoked bv either of two modes of stimulation. Throuqh * direct stimulation of the cord, two major potentials, which were conducted bidirectionallv along the posterior part of the lateral and posterior funiculi respectively, were measured in the epidural space. Wifh percutaneous stimulation of peripheral nerves in the extremities, ascending evoked potentials were picked up around the entry zones of the nerve roots or at the level of the cauda equina. Positivity of these potentials was most remarkable at the spinal level of a cord injury or tumorous lesion so that it was a manifestation of a conduction block within a well circumscribed area in the conducting pathways. Reduction in amplitude of a component of these potentials was noticed with or without such positivity in various conditions of spinal canal stenosis, including spondylotic myelopathy. A polyphasic pattern with either short or long duration was not rare in both cases with spinal cord tumour and in those with Evoked spinal potential measspinal stenosis. was helpful to visualise not only the urement site and the extent but the type of pathology in neural structures along the spinal canal. A-7.05 TEMPORAL LOCATION EFFECT OF NOISE BURST INTENSITY ON AUDITORY EVOKED POTENTIALS. Y. (Tsukuba, Japan) Kuchinomachi This study was conducted to explore the hypothesis that the Nl-P2 component of the auditory evoked potential exclusively reflects the stimulus intensity around 30 msec after sound onset rather than immediately after sound onset or the simple integrated value of sound energy. Subjects were randomly presented with three types of brief noise burst which differed in temporal
Reaction time (RT) of finger extension increases when vocalization is simultaneously executed. This phenomenon is attributed to the interference effect of the simultaneous performances. To analyse how attention influences the interference effect and what difference is there between the performance of the left and right sides. we examined RTs of left and rioht finqer extension of 8 subjects in 4 conditions; with or without simultaneous vocalization, and with or without a warning signal (preparatory interThe RT of finger extension was val 2 set). faster with a warning signal than without it. The shortening of RT with a warning signal was the same in both the left and right manual reWith simultaneous sponses without vocalization. vocalization, the RT shortening with a warning signal was less on the right side than the left, that is, the interference effect of the right manual-vocal simultaneous performance became larger than that of the left. This suggests that the hemispheric differentation regarding the interference effect of the simultaneous performance is related to the attentional state. B-I.01 MOTOR TIME AS A MEASURE OF RAPID FORCE N. Irie, R. Nakamura and H. NagaGENERATION. saki (Narugo, Japan) To evaluate the rapid force generation of a muscle, motor time (MT) or EMG summation time, the latency between the EMG onset and the initiation of movement was examined during rapid extension of the knee joint in normal subjects and patients In the sitting with quadriceps insufficiency. posture, MT of the vastus mehialis was measured at varied anales of the knee joint (90' - O')MT correlated linearly with the jntegrated EMG during the period of MT, and could be regarded as proportional to the generated muscle force. MT, both for the normal and the affected knees, increased proportionally with the increased load
of low voltage (l.OV, 0.5msec, 14-lHz, 2-5min). Based on these results, we developed a new stimulating apparatus ("SLEEPY") for the clinical use of electrosleep in man in cooperation with Homer Ion Institute (Tokyo). Clinical trials of "SLEEPY" (3.4V. 0.2msec. 14-1Hz. 30 min).were carried out on>60 insomniac subjects having no significant psychiatric, and organic For the assessement of efficacy, disturbances. a comparison between sleep questionnaires before and after use of "SLEEPY" at home was statistically made by sign test. The results showed sianificant effects (P
during the different stages of sleep under various conditions in 10 cats were determined by electrical stimulation through electrodes chronically implanted in the nucleus ventralis POStero-lateralis thalami (VPL). The arousal' thresholds durina PS were sianificantlv hiaher and more variable than those-found during Tight Especially, sleep and deep sleep in our study. the thresholds in the PS periods accompanied by eye movements were significantly higher than in PS periods without eye movements. In addition, when the PS period was divided into three parts (first. middle. last oeriod) accordina to the time course from PS onset, the threshold in the last period was significantly lower compared with the other two periods. Finally, we also investigated the changes in arousal thresholds accompanying Pavlovian alimentary conditioning when VPL stimulation was employed as conditioned stimulus. After the establishment of conditioning, the arousal thresholds in PS and light sleep periods were significantly lowered compared with those before conditioning. A-II.09 ANALYSIS OF THE DREAM CONTENTS IN JAPANESE COLLEGE STUDENTS BY REMP-AWAKENING TECHNIQLE. J. Matsumoto, T. Yamanaka and Y. Morita (Tokushima, Japan) The present study was performed on 39 japanese college students in Tokushima, aged from 19 to 21 years, using the REMP-awakening technique (collecting dreams by awakening the students during the period of REM sleep) which was established by Dement and others. The results consist of two parts, one at the lodging by observation (6 males, 12 females), the other at the laboratory by polygraphic recording (11 males, 10 females). All the procedures of dream reporting were recorded on magnetic tape and transcribed later. The contents of 297 dreams (220 in the lodging, 77 in the laboratory) were analysed and classified according to the Hall-Van de Castle scale (nature, material, character, activity, emotional element, etc.). The incidence of dreams was compared with that obtained from American college students by Hall and Van de Castle. Relationships between dream contents and polygraphic phenomena were also investigated. B-19.05 PEAK FREQUENCY OF ALPHA ACTIVITY SHIFTS DURING MENTAL TASKS: HEMISPHERIC DIFFERENCES. M. Osaka (Kyoto, Japan) Power spectral analyses were made of EEG recorded during arithmetic and visuo-spatial tasks: (1) simple addition, (2) complex addition, (3) visual imaqery, (4) mental rotation and (5) resting state.. Using 20 right-handed normal‘subjects, EEGs were recorded for 2 min from the right-and the left occipital and frontal sites. The results showed that (1) the peak
S54
frequencies of the power spectrum within the alpha band shifted markedly from 0.1 to about 0.8 Hz as the task changed from the resting state to the mental task. Furthermore, (2) the peak frequency significantly shifted toward a higher range in the left hemisphere during the complex addition task, whereas (3) the peak frequency markedly shifted toward a higher range in the right hemisphere during the mental rotation task. This suggests that the peak frequency of alpha activity is closely related to the difficulty of the mental task. Moreover, hemispheric differences found here indicate lateral asymmetry of brain function for verbal and nonverbal information processing.
location-of the maximum (plateau) stimulus intensity. In one type the rise and fall times were 5 msec, and the plateau duration was 35m sec. In other two types, the rise and fall times were, respectively, 5 msec and 30 msec or the reverse, and their plateau durations were 10 msec. The amplitude of the Pl-Nl component in in the evoked potential seems to correspond with the sound energy simply integrated within 45 mset duration. BY contrast, the amolitude of the Nl-P2 component-was not greatly affected by the temporal integration of sound energy, and its amplitude was significantly larger when the maximum intensity appeared 30 msec after the onset than when it appeared immediately after the onset. This result supports the above hypothesis.
C-5.04 OBSERVATIONS ON SPINAL CORD OR NERVE ROOT LESIONS THROUGH EVOKED SPINAL POTENTIAL MEASUREMENT. T. Kurokawa, N. Tsuyama, H. Tanaka, M. Kobayashi, H. Machida, K. Nakamura, T. Iizuka, Y. Hoshino and T. Imai (Tokyo, Japan)
D-9.01 THE INFLUENCE OF ATTENTION ON THE INTERFERENCE EFFECT OF MANUAL-VOCAL SIMULTANEOUS PERR. Nakamura and T. Chida (Narugo, FORMANCES. Japan)
A review was conducted of 283 patients who underwent evoked spinal action potential measurement. Spinal action potentials were evoked bv either of two modes of stimulation. Throuqh * direct stimulation of the cord, two major potentials, which were conducted bidirectionallv along the posterior part of the lateral and posterior funiculi respectively, were measured in the epidural space. Wifh percutaneous stimulation of peripheral nerves in the extremities, ascending evoked potentials were picked up around the entry zones of the nerve roots or at the level of the cauda equina. Positivity of these potentials was most remarkable at the spinal level of a cord injury or tumorous lesion so that it was a manifestation of a conduction block within a well circumscribed area in the conducting pathways. Reduction in amplitude of a component of these potentials was noticed with or without such positivity in various conditions of spinal canal stenosis, including spondylotic myelopathy. A polyphasic pattern with either short or long duration was not rare in both cases with spinal cord tumour and in those with Evoked spinal potential measspinal stenosis. was helpful to visualise not only the urement site and the extent but the type of pathology in neural structures along the spinal canal. A-7.05 TEMPORAL LOCATION EFFECT OF NOISE BURST INTENSITY ON AUDITORY EVOKED POTENTIALS. Y. (Tsukuba, Japan) Kuchinomachi This study was conducted to explore the hypothesis that the Nl-P2 component of the auditory evoked potential exclusively reflects the stimulus intensity around 30 msec after sound onset rather than immediately after sound onset or the simple integrated value of sound energy. Subjects were randomly presented with three types of brief noise burst which differed in temporal
Reaction time (RT) of finger extension increases when vocalization is simultaneously executed. This phenomenon is attributed to the interference effect of the simultaneous performances. To analyse how attention influences the interference effect and what difference is there between the performance of the left and right sides. we examined RTs of left and rioht finqer extension of 8 subjects in 4 conditions; with or without simultaneous vocalization, and with or without a warning signal (preparatory interThe RT of finger extension was val 2 set). faster with a warning signal than without it. The shortening of RT with a warning signal was the same in both the left and right manual reWith simultaneous sponses without vocalization. vocalization, the RT shortening with a warning signal was less on the right side than the left, that is, the interference effect of the right manual-vocal simultaneous performance became larger than that of the left. This suggests that the hemispheric differentation regarding the interference effect of the simultaneous performance is related to the attentional state. B-I.01 MOTOR TIME AS A MEASURE OF RAPID FORCE N. Irie, R. Nakamura and H. NagaGENERATION. saki (Narugo, Japan) To evaluate the rapid force generation of a muscle, motor time (MT) or EMG summation time, the latency between the EMG onset and the initiation of movement was examined during rapid extension of the knee joint in normal subjects and patients In the sitting with quadriceps insufficiency. posture, MT of the vastus mehialis was measured at varied anales of the knee joint (90' - O')MT correlated linearly with the jntegrated EMG during the period of MT, and could be regarded as proportional to the generated muscle force. MT, both for the normal and the affected knees, increased proportionally with the increased load