Integrating EEG/MEG and fMRI: 99-M-0172

脑磁图数据记录和信号处理方法的发展非常成功。对工作记忆任务和听觉处理任务的研究表明，有能力定位大脑的激活，并解决相位与紧张性活动的问题。我们正在调查表型指标，这些指标将适用于许多相关研究，特别是兄弟姐妹项目。 认知激活期间的脑磁图记录已经显示出以与功能磁共振非常相似的方式进行定位的能力。具体地说，已经发现皮层水平的β去同步化与大胆的激活结果一致。然而，脑磁图/脑电允许使用其他成像技术所不能提供的时间信息。利用先进的信号处理技术，已经证实了大脑各区域之间的相位关系。我们的结果表明，大脑结构和功能的测量是寻找易感基因的有力工具。进一步的研究已经证明了在杏仁核等更深层次的结构中定位信号的能力，并研究了视觉感知与伽马波段信号的关系。我们还发现，前扣带回皮质的GABA浓度与空间定位的静息MEGβ频带功率相关。我们预计，进一步的研究将揭示伽马功率和GABA系统之间的额外关系。 精神分裂症患者在工作记忆任务中的激活程度，特别是以β去同步化为指标的额叶区域，与健康的兄弟姐妹和正常对照志愿者相比存在差异。对这种激活的进一步研究揭示了与研究得很好的COMT标记的基因型的交互作用。我们发现，在对即将到来的任务需求的预期中，存在着前额叶皮质活动的调制。这一预备信号可能对研究患者群体的认知功能障碍很重要。 网络模式和动力学的差异是理解临床组潜在病理的关键。Bassett等人已经证明，患者群体中的功能网络差异可以被证明，并与认知活动的行为结果有关。Rutter等人已经证明，即使在休息时，精神分裂症患者的伽马功率比正常受试者也有所降低。这些发现是否与状态或特征差异有关，以及是否存在遗传关联，还有待观察。我们发现，参与这些记忆任务的大脑区域的时间序列有明显的模式，显示出不同受试者的不同个体差异。这些差异将形成在患者群体中的基因型式和证据的基础。

Development of MEG data recording and signal processing methods has been very successful. Studies of working memory tasks and auditory processing tasks have shown the ability to localize brain activation and to address issues of phasic versus tonic activity. We are investigating phenotype measures that will be applicable in many related studies and specifically the sibling project. MEG recording during cognitive activation has shown the ability to localize in very comparable fashion to fMRI. Specifically beta desynchronization at the cortical level has been found to agree with BOLD activation results. However, the MEG/EEG allows for temporal information not possible with other imaging techniques. Phasic relationships across brain areas have been demonstrated using advanced signal processing techniques. Our results show that measures of brain structure and function represent powerful tools to find susceptibility genes. Further studies have demonstrated the ability to localize signals in deeper structures such as the amygdala and to investigate the relation of visual awareness to gamma band signals. We have also found that GABA (gamma-aminobutyric acid) concentration in the anterior cingulate cortex correlates with spatially localized resting MEG beta band power. We expect that further investigation will reveal addtional relationships between gamma power and GABA systems. Diffrerences in the degree of activation especially in frontal regions as indexed by beta desynchronization during a working memory task have been found between patients with schizophrenia compared to well siblings and normal control volunteers. Further investigation of this activation has revealed an interaction with genotype for the well studied COMT marker. We have found there is a modulation of prefrontal cortex activity that occurs in anticipation of the upcoming task demands. This preparatory signal may be important in investigating cognitive dysfunction in patient populations. Differences in network patterns and dynamics are key to understanding underlying pathology in clinical groups. Bassett et al have shown that functional network differences in patient groups can be demonstrated and related to behavioral outcomes on cognitive activities. Rutter et al have shown that even at rest patients with schizophrenia have gamma power reduction compared to normal subjects. It remains to be seen whether these finding relate to state or trait differences and if there are genetic associations. We have found distinct patterns of the temporal sequence of brain regions involved in these memory tasks that show a variety of individual differences across subjects. These differences will form the basis for genotypic patterns and dscrimination in patient groups.