Neural correlates for recognition memory --An investigation using functional magnetic resonance imaging and event related potential--

本研究采用功能磁共振成像（fMRI）和事件相关电位（ERP）研究了正常志愿者情景记忆的神经相关因素。功能磁共振成像（fMRI）能以高的空间分辨率测量与认知任务相关的脑活动，而事件相关电位（ERP）能以高的时间分辨率提供神经反应的信息。结合这两种模式提供了一个独特的机会，调查在何处和何时在人脑中发生的特定的神经响应。第一项研究探讨是否血氧水平依赖（BOLD）的信号获得的功能磁共振成像和电位测量ERP将相互关联。为此，正常志愿者在执行面部识别任务时，分别接受了fMRI和ERP。体素的相关性分析显示，BOLD信号和ERP幅度的脸减去房子的条件下显着相关的右颞区。结果表明， ...更多信息 在第二项研究中，我们采用fMRI和ERP技术对不同组别的被试进行了图片再认记忆的研究。在功能磁共振成像研究中，成功识别所研究的项目涉及额顶叶区域的神经激活，而在ERP研究中，这种认知过程在刺激开始后约500 ms在顶叶电极中诱发大的正电位。这两种反应可能反映了同一组神经元的神经活动，而受试者正确地识别了所研究的项目。另外，fMRI研究发现左前顶叶区在情景记忆的回忆过程中起着重要作用。最后，利用fMRI和正常老年人对图片再认记忆进行了研究。这些老年受试者身体健康，独立生活在社区。关于成功提取的神经相关性，老年组显示出较少的激活在左侧海马和更多的激活在压后皮质比年轻组。少

The present study investigated neural correlates for episodic memory in normal volunteers using functional magnetic resonance imaging (fMRI) and event-related potential (ERP). fMRI can measure brain activity associated with cognitive tasks with high spatial resolution and ERP provides information of neural responses with high temporal resolution. Combining these two modalities offers a unique opportunity to investigate where and when a particular neural response occurs within the human brain.The first study examined whether blood-oxygen-level-dependent (BOLD) signal obtained by fMRI and electrical potentials measure by ERP would correlate each other. For this purpose, normal volunteers underwent both fMRI and ERP in separate sessions while they were performing a face recognition task. A voxel-by-voxel correlation analysis revealed that BOLD signal and ERP amplitude for face minus house condition significantly correlated in the right temporal areas. The results indicated a close relatio … More nship between the data obtained by using the two modalities.In the second study, a recognition memory for pictures was investigated using fMRI and ERP in different group of subjects. In an fMRI study successful recognition of studied items involved neural activation in the fronto-parietal areas, while in an ERP study, this cognitive process evoked large positive potential in parietal electrodes at around 500 ms after stimulus onset. These two responses probably reflected neural activity of the same group of neurons while the subjects correctly recognized the studied items. In addition, fMRI study revealed that the left front-parietal areas are particularly important for recollective process of episodic memory.Finally, recognition memory for pictures was studied using fMRI and normal elderly subjects. These elderly subjects were healthy and independently living in the community. With regard to the neural correlates for successful retrieval, the elderly group showed less activation in the left hippocampus and more activation in the retrosplenial cortex than the young group. Less