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Working memory used for a goal-directed behavior has limited capacity. In this article, we examined what the specific function of the working memory capacity as the controlled attention function was. In addition, we discussed how working memory capacity affected the everyday situations in terms of the mind wandering. In the study using event-related potential (ERP), the analysis examined relationship between individual difference in working memory capacity and ERP component involved mind wandering. The amplitude of ERP component involved mind wandering for low-span group has smaller than high-span group. This result suggested possibility that many mind wandering occurred in low-span group during the tasks. Finally, we discussed further research and educational aspect based on the relationship between working memory capacity and attention., 「何かをするために使われる記憶」であるワーキングメモリには，制限された容量が存在する。本論文では，注意制御機能としてのワーキングメモリ容量の具体的な機能は何なのか検証した。また，この機能が日常場面にどのように関わるのか，マインドワンダリングという観点から考察し，事象関連電位を用いた研究から，ワーキングメモリ容量の個人差とマインドワンダリングに関連した事象関連電位成分を検証した。ワーキングメモリ容量低群ほど，マインドワンダリングが生じることで事象関連電位の振幅が減衰した可能性を示唆した。最後に，ワーキングメモリ容量と注意の関係を踏まえた教育的場面への応用について論じ，今後の研究可能性を考察した。

注意欠陥/多動性障害(AD/HD)は不注意,多動,衝:動性を3主症状とする軽度 発達障害である。AD/HDについては精神生理学的研究が比較的多くなされているが,ほとん どの研究では課題刺激による結果を検討するに留まっており,それは情報処理過程における"最 終産物"を見ているに過ぎない。そこで我々は"最終産物"になるまでの,課題刺激によって誘発 された脳の活動を調べることが可能な事象関連電位(ERP)に注目して検討を行なった。その結 果,AD/HD群では健常群に比べてP300の振幅の低下と潜時の延長が認められた。さらに注意 関鰍であるnegative difference(Nd)とmismatch negativity(MMN)も低振幅でありた。こ れらの成績から,AD/HDには何らかの認知障害があり,さらに情報の統御処理と自動処理の 両過程においても障害のあることが示唆された。この稿ではAD/HDにおけるERPについての 我々の研究を中心として,現在までの知見とそれらが臨床的にどのような意味を持つのかにつ いて記した。

The present study investigated whether the attention to and processing of expression modulated the event-related potentials (ERP) elicited by face. In two experiments, a total of 24 adult participants performed go/no-go tasks where the target was defined by the facial expression (smile/anger) or by the person identity (male/female). Two experiments differed only in the response time limit. Results in the experiment with a severer limit showed that the no-go-trial-ERPs between 230-300 ms after the stimulus onset were more negative than the go-trial-ERPs, and this difference was larger when participants processed person identity than when they attended to facial expression. This suggested that emotional information could alter the neuronal activities involved in response inhibition processes.

A recent event-related potentials (ERP) study revealed that aspectual mismatch contexts evoked a significantly greater frontal negativity between 400-700ms. Another magnetoencephalography (MEG) study revealed that the aspectual mismatch is associated with increased activities of the anterior midline field (AMF), localized in ventromedial prefrontal cortex. In this study, we conducted an electrophysiological study of real-time computation for Japanese aspectual mismatch using ERP. We recorded ERP response to the sentences that included aspectual mismatch. The result indicated that the N400 component associated with semantic anomaly was not elicited in the aspectual mismatch condition, suggesting that semantic computation for an aspectual mismatch is different from that of a semantic mismatch between words and their discourse context. Additionally, a significant negativity was elicited in the 350-750ms time-window in the left anterior site. Considering the scalp distribution, this negativity for the coercion condition is likely to be a LAN effect, suggesting that aspectual coercion might enhance the cortical activation related to semantic ambiguity.

By using event-related potentials (ERP, Experiment 2) and reaction times (RT, Experiment 1), the present study examined interlanguage differences between Japanese and English in audio-visual speech perception (Kuhl, Tsuzaki, Tohkura, & Meltzoff, 1994; Sekiyama & Burnham, 2008; Sekiyama & Tohkura, 1991, 1993). There were an auditory-only (AO) and a congruent auditory-visual (AV) conditions. In Experiment 1, RTs showed opposite tendencies between English-language (EG) and Japanese-language(JG) groups for the AO-AV relationship: the additional congruent visual information speeded up the speech perception processes for the EG, but it slowed down the processes for the JG. Thus, the visual influence was promoting for the EG but disturbing for the JG. In Experiment 2, different ERP patterns were found between the EG and JG: Whereas the visual influence was sustained (maintained from N1 to P2) in the EG, the influence was transient (limited only to N1) in the JG. The ERP and RT data were both consistent with the reported interlanguage differences that the JG perceivers use visual information to the less extent than the EG perceivers do.

Recently, electrophysiological measures, especially event-related potentials (ERP), have been increasingly used for investigating the brain mechanisms of music perception. This article aims to briefly review the ERP studies on harmony processing, one of important aspects of music experience, and to identify problems to solve in future research. It has been repeatedly reported that an ERP component termed the early right anterior negativity (ERAN) was elicited in response to chords harmonically inappropriate or incongruent with musical context. However, the nature of cognitive processes reflected in this negativity is still unclear. In addition, similarities and differences between ERAN and the other brain responses, e.g., MMN and N5, obscure the correspondence between these indices and different cognitive processes involved in music perception. The validity of research on harmony processing, and contributions of these studies to the musical therapy domain were also discussed.

To investigate how indistinct information in a nonverbal stimulus affects the categorizing process of that stimulus, we observed the event-related potentials (ERP) elicited by arrows, which indicate distinct (rightlleft or upward) or indistinct (to some extent different from rightlleft or upward) directions. In three experiments, participants were required three different judgments on the direction of these arrows. The results from these experiments suggest that the N2 and P3b components of ERP relate to the processes on which discrimination and categorization of nonverbal stimuli depend, while it was not demonstrated the N400 is sensitive to the incongruity between verbal and nonverbal directional information.

漢字熟語を処理する際の大脳半球機能差に性差がみられるかどうかを成人について検討した。右利きの大学生，および大学院生を被験者として，継時的に提示される2つの漢字熟語の関係を判断する際の脳波を測定し，平均加算波形で表される事象関連電位を比較した。形態処理条件では，先行刺激（標準刺激）と後続刺激（比較刺激）に同一の漢字があるか，否かの判断をさせた。音韻処理条件では，2つの刺激（熟語）の読みが同一であるか，否かを判断させた。意味処理条件では，2つの刺激が同一カテゴリーに属する熟語であるか，否かを判断させた。Central導出の形態処理条件で，男子では右半球の機能優位が観察されたが，女子においてはこのような優位性がみられなかった。音韻処理条件，意味処理条件では，Prietal導出で左半球優位が観察されたが性差はみられなかった。, Sex differences of cerebral hemisphere pecialization were examined when subjects were processing the words under three context conditions. Subjects were asked to match successively presented two Kanji words in graphmic, phenomic or semantic contexts. Event related potentials (ERP) were recorded from C3, C4, P3, P4 of normal right-handed adults. In graphemic processing, P300 potentials calculated by grand average method were signifficantly larger in the right hemisphre than those in the left hemisphre in male subjects. This superiority of the right hemisphre was not observed in female subjects. In phonemic and semantic processings, the left hemisphre became superior, but sex differences were not found.

The present study investigated whether the attention to and processing of expression modulated the event-related potentials (ERP) elicited by face. In two experiments, a total of 24 adult participants performed go/no-go tasks where the target was defined by the facial expression (smile/anger) or by the person identity (male/female). Two experiments differed only in the response time limit. Results in the experiment with a severer limit showed that the no-go-trial-ERPs between 230-300 ms after the stimulus onset were more negative than the go-trial-ERPs, and this difference was larger when participants processed person identity than when they attended to facial expression. This suggested that emotional information could alter the neuronal activities involved in response inhibition processes.

人が平地から標高5000mを越える高所に移動すると頭痛, 嘔吐, 不眠といった自律神経系の機能障害に起因する症状に加えて, 感覚および運動機能障害, 判断力, 記憶力の低下等の大脳および小脳の機能障害が現れる. 本調査は, 電気生理学的手法を用いて, これらの脳機能障害のメカニズムを解明するための手がかりを得ることが目的である., It is well known that the hypoxic environment produced by sojourn at high altitudes often induces the disorders in the sensory and motor system of the brain as well as behavioral and physiological changes such as anorexia nausea or insomnia. These symptoms may be produced mainly by combined effect of hypoxia and hypothermia at high altitudes. The purpose of this study is to find the changes in the electrical activities of the human brain at high altitudes occurring in association with brain symptoms and disorders. Twenty one subjects were selected from the members of the Kyoto University Himalayan Medical Expedition in 1990. They spent about two or three months at high altitudes above 5000 meters. Recordings of the event related potentials (ERP) which is referred to P3 or P300, and auditory evoked potentials (AEP) were made at sea level and at high altitudes, usually at the base camp. The subject concentrated to a tone, and responded by pressing a push-button with the thumb. Paired tones separated by an interstimulus interval of 1-4 seconds were given to the subjects required to respond to the second tone. The electroencephalogram (EEG) was recorded from silver-chloride disc electrodes at vertex (Cz), with left earlobe as reference. The right earlobe was connected to the ground, usually. The amplified EEG was stored on magnetic tapes using a frequency modulated tape recorder for off-line analysis by an averaging computer after returning to our laboratories. Individual potentials were averaged over 30-50 trials. In 13 subjects significant decrease in ERP (P3) at high altitudes was observed compared with control recordings at sea level. Seven subjects suffered from the brain syndrome. Mean values of the P3 were 7.9 + 5.1 uV at high altitude and 18.5 + 9.2 uV (N=13) at sea level. Significant decrease in AEP was also observed. Mean values of the AEP were 9.6 + 5.8 uV at high altitude and 15.8 + 6.2 uV (N=21) at sea level. It was inferred that ERP is more sensitive to the hypoxic environment compared with AEP.

A new method of Dynamic Topography of auditory event-related potentials (ERP) was reported with clinical application. ERPs were recorded during presentation of auditory stimuli. The stimuli consisted of 1 KHz tone-burst (inattentive) and 2 KHz tone-burst(attentive). The probabilities of frequent stimuli and rare stimuli were 0.8 and 0.2, respectively. The subjects were instructed to count the number of the rare tones. The scalp EEG from 16 scalp electrodes referenced to linked ears and positioned according to the international 10-20 system was recorded. ERPs to attentive stimuli were topographically demonstrated using 「Topography No.200 SPJ」 These two-dimensional maps were recorded as a series of pictures by video tapes. We call this method Dynamic ERP Topography. Case 1 was 67-years-old male with memory disturbance caused by left frontal lobe infarction. Case 2 was 57-years-old female wiht multi-infarct dementia. In both two patients with impaired memory, the patterns of Dynamic ERP Topography showed different ones from healthy subjects. In conclusion, Dynamic ERP Topography would be a useful method to investigate the disturbance of information-processing system in psychiatric disorders., 論文