Neurology & clinical neurophysiology : NCN最新文献_第8页

The auditory n100m response reflects changes in speech fundamental frequency. 听觉的n100m反应反映了语音基频的变化。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

A M Mäkelä, P Alku, P J C May, V Mäkinen, H Tiitinen

引用次数: 0

Quantitative results concerning effects of repetitive transcranial magnetic stimulation on mesoscopic brain activity. 重复经颅磁刺激对中观脑活动影响的定量结果。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

O T Holzner, E Schöll

引用次数: 0

Periodic glottal excitation and formant frequencies in the perception of vowels. 元音感知中的周期性声门兴奋和形成峰频率。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

H Tiitinen, A M Mäkelä, V Mäkinen, P J C May, P Alku

引用次数: 0

Multimodal Imaging of Somatosensory Evoked Cortical Activity 体感觉诱发皮层活动的多模态成像

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30 DOI: 10.1515/bmte.2001.46.s2.237

C. Ramon, J. Haueisen, T. Richards, K. Maravilla, H. Panagiotides

引用次数: 4

Magnetocardiography of animals in magnetically shielded environment with active compensation. 主动补偿磁屏蔽环境下动物的心脏磁图。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

H E Horng, S H Liao, S J Hsu, H C Yang, J Y Wu, C C Chen, C H Wu, C C Wu

引用次数: 0

Modulation of neuromagnetic oscillatory activity during the observation of oro-facial movements. 观察面部运动时神经磁振荡活动的调节。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

S D Muthukumaraswamy, B W Johnson, W C Gaetz, D O Cheyne

{"title":"Modulation of neuromagnetic oscillatory activity during the observation of oro-facial movements.","authors":"S D Muthukumaraswamy, B W Johnson, W C Gaetz, D O Cheyne","doi":"","DOIUrl":"","url":null,"abstract":"A number of MEG/EEG studies have shown modulation of endogenous sensorimotor (mu and beta) rhythms during the observation of hand movements. These modulations are similar to patterns that occur during execution of movement and it has been hypothesised that the neural substrates of these rhythms may play a role in action representation and understanding the actions of others. In this experiment we wished to determine whether similar responses would be obtained during the observation of oro-facial movements. Neuromagnetic recordings (151 channels, CTF Systems) were obtained from six healthy subjects while they (1) observed a video of an experimenter making oro-facial movements (2) imitated the same movements and (3) observed hand movements. Source scanning using synthetic aperture magnetometry (SAM) was used to find changes in source power between these active conditions compared to pre-stimulus control conditions where no movement occurred. SAM images were created with 5 mm resolution in the beta (15-35 Hz) and mu (8-15 Hz) bands and showed source power decreases over parietal, occipital and sensorimotor areas. Time-frequency analysis of virtual SAM sensors from sensorimotor areas showed event-related desynchronisation of mu and beta bands following the onset of movement in all three conditions. These data demonstrate comparable activations of visuomotor mechanisms during observation or imitation of mouth movements and during observation of hand movements. These results support the notion that sensorimotor mechanisms play a role in achieving a representation of the oro-facial gestures of others.","PeriodicalId":83814,"journal":{"name":"Neurology & clinical neurophysiology : NCN","volume":"2004 ","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24895644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A grid computing infrastructure for MEG data analysis. 用于MEG数据分析的网格计算基础结构。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

S Nakagawa, T Kosaka, S Date, S Shimojo, M Tonoike

{"title":"A grid computing infrastructure for MEG data analysis.","authors":"S Nakagawa, T Kosaka, S Date, S Shimojo, M Tonoike","doi":"","DOIUrl":"","url":null,"abstract":"Magnetoencephalography (MEG) is widely used for studying brain functions, but clinical applications of MEG have been less prevalent. One reason is that only clinicians who have highly specialized knowledge can use MEG diagnostically, and such clinicians are found at only a few major hospitals. Another reason is that MEG data analysis is getting more and more complicated, and deals with a large amount of data, and thus requires high-performance computing. These problems can be solved by the collaboration of human and computing resources distributed in multiple facilities. A new computing infrastructure for brain scientists and clinicians in distant locations was therefore developed by the Grid technology, which provides virtual computing environments composed of geographically distributed computers and experimental devices. A prototype system connecting an MEG system at the AIST in Japan, a Grid environment composed of PC clusters at Osaka University in Japan and Nanyang Technological University in Singapore, and user terminals in Baltimore was developed. MEG data measured at the AIST were transferred in real-time through a 1-GB/s network to the PC clusters for processing by a wavelet cross-correlation method, and then monitored in Baltimore. The current system is the basic model for remote-access to MEG equipment and high-speed processing of MEG data.","PeriodicalId":83814,"journal":{"name":"Neurology & clinical neurophysiology : NCN","volume":"2004 ","pages":"36"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24895653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The discovery of slowness--recent progress in DC-MEG research. 慢速的发现——DC-MEG研究的最新进展。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

B M Mackert

{"title":"The discovery of slowness--recent progress in DC-MEG research.","authors":"B M Mackert","doi":"","DOIUrl":"","url":null,"abstract":"The non-invasive electrical recording of Direct Current (DC) phenomena in the frequency range below 0.1 Hz, e.g., occurring in metabolic injuries to brain cells in stroke or migraine (anoxic depolarization, peri-infarct depolarization, spreading depression), is technically restricted due to large drift artifacts caused by electrochemical instabilities at the electrode-skin interface. This limitation could be overcome by invasive approaches only. However, as early as 1969 first magnetic fields in this frequency range have been recorded over the human torso by oscillating the subject vertically in front of a magnetic field detector using a see-saw. By this technique the DC field is conversed to a higher frequency, where the external noise level is less. In the last decade, the modulation based DC-magnetoencephalography (DC-MEG) has been methodically refined, which allowed monitoring low-amplitude magnetic fields in this frequency domain arising not only from injured tissue, but also generated by functional cortical activation. Furthermore, the combination of DC-MEG and NearInfraRed Spectroscopy (NIRS) opens up a new avenue to study cortical neurovascular coupling, as vascular and neuronal activations could be analyzed simultaneously even without averaging in a single-trial mode. Recordings inside the novel magnetically shielded room (BMSR-2 of the Physikalisch-Technische Bundesanstalt, Berlin) exhibiting an extremely low background noise level in the DC frequency range, and alleviating the need of sensor-to-source modulation, allow to resolve additionally the short-term (subsecond) dynamics of neuronal DC-processes.","PeriodicalId":83814,"journal":{"name":"Neurology & clinical neurophysiology : NCN","volume":"2004 ","pages":"41"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25184677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Predictor of cognitive deterioration in elderly subjects by auditory-evoked magnetic signal using magnetoencephalography. 脑磁图听觉诱发磁信号对老年受试者认知衰退的预测。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

H Oe, H Naritomi, A Kandori, K Ogata, T Miyashita, S Sakoda

{"title":"Predictor of cognitive deterioration in elderly subjects by auditory-evoked magnetic signal using magnetoencephalography.","authors":"H Oe, H Naritomi, A Kandori, K Ogata, T Miyashita, S Sakoda","doi":"","DOIUrl":"","url":null,"abstract":"Recent development of auditory-evoked magnetoencephalography (A-MEG) made it possible to measure interhemispheric neural conduction time (INCT) of auditory impulses. We estimated INCT with A-MEG and cognitive function with mini-mental state examination (MMSE) in 85 elderly patients with chronic dizziness (CD) and found that INCT was negatively correlated with MMSE scores (p<0.001). In 11 of 85 patients whose MMSE scores were within the normal range, A-MEG and MMSE were repeated for the subsequent 4 years to find longitudinal changes in INCT and cognitive function. The 11 patients were divided into two groups according to the baseline INCT values, such as Group A with normal INCT (n=7) and Group B with abnormally prolonged INCT (n=4). In Group A, INCT and MMSE scores remained within the normal range throughout the 4-year period. In Group B, INCT showed the tendency towards progressive prolongation during the follow-up period, and MMSE scores decreased to abnormally low levels at the third or fourth follow-up year in all the patients. The present results suggest that rapid neural interaction of both cerebral hemispheres is needed to maintain normal cognitive function. Abnormal INCT prolongation in elderly subjects suggests subclinical cortical network dysfunction and may predict the future development of cognitive deterioration.","PeriodicalId":83814,"journal":{"name":"Neurology & clinical neurophysiology : NCN","volume":"2004 ","pages":"76"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25184974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Auditory scene analysis and sensory memory: the role of the auditory N100m. 听觉场景分析与感觉记忆:听觉N100m的作用。

Neurology & clinical neurophysiology : NCN Pub Date : 2004-11-30

P J C May, H Tiitinen

{"title":"Auditory scene analysis and sensory memory: the role of the auditory N100m.","authors":"P J C May, H Tiitinen","doi":"","DOIUrl":"","url":null,"abstract":"We consider the neural dynamics underlying auditory streaming, the perceptual grouping of transient auditory events, by using neural modeling and magnetoencephalographic (MEG) measurements in humans. We demonstrate that spatial variations in the strength of feedback inhibition leads to differential amplitude modulation (AM) tuning resembling that found in animal models. In our model, neurons respond selectively to stimuli presented at different onset-to-onset interstimulus intervals (ISIs), and their summed activity (corresponding to the MEG signal) exhibits both transient and sustained responses (SRs) at fast ISIs. In MEG measurements utilizing 2-s trains of 50-ms stimuli presented at 0-1950 ms ISIs, we observed the transient N100m and SRs predicted by the model, with a prominent SR emerging for discrete stimuli at ISIs below 200 ms. Our results explain why, at fast stimulus rates, the amplitude of the auditory N100m appears to be strongly attenuated even though auditory cortex continues to respond vigorously to the stimuli. The results suggest that the longer and shorter forms of auditory sensory memory may be reflected in the N100m and the SR, respectively. As the emergence of the SR coincides with the stimuli being perceived as auditory streams, our study suggests that auditory sensory memory as indexed by transient and sustained cortical activity might underlie auditory scene analysis.","PeriodicalId":83814,"journal":{"name":"Neurology & clinical neurophysiology : NCN","volume":"2004 ","pages":"19"},"PeriodicalIF":0.0,"publicationDate":"2004-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25188025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0