海马体,各种重要认知过程的活动中心,是研究人员和临床医生越来越感兴趣的目标。脑磁图(MEG)是一种有吸引力的技术,用于成像功能的光谱-时间方面,例如,神经振荡和网络时序,特别是在浅皮质结构中。然而,作为源深度的函数的MEG信噪比的下降意味着MEG用于研究更深的大脑结构的效用,包括海马,不太清楚。为了确定MEG是否可用于检测和定位海马的活动,我们对现有文献进行了系统回顾,发现用MEG成功检测到源自海马的振荡神经活动.先决条件是使用既定的实验范式,充分的共同注册,正向建模,分析方法,信噪比的优化,和协议试验设计,最大限度地提高海马活动的对比度,同时最大限度地减少来自其他大脑区域的对比度。虽然尚未将活动定位到海马体内的特定子结构,我们为提高此类工作的可靠性提供建议。
The
hippocampus, a hub of activity for a variety of important cognitive processes, is a target of increasing interest for researchers and clinicians. Magnetoencephalography (MEG) is an attractive technique for imaging spectro-temporal aspects of function, for example, neural oscillations and network timing, especially in shallow cortical structures. However, the decrease in MEG signal-to-noise ratio as a function of source depth implies that the utility of MEG for investigations of deeper brain structures, including the
hippocampus, is less clear. To determine whether MEG can be used to detect and localize activity from the
hippocampus, we executed a systematic review of the existing literature and found successful detection of oscillatory neural activity originating in the
hippocampus with MEG. Prerequisites are the use of established experimental paradigms, adequate coregistration, forward modeling, analysis methods, optimization of signal-to-noise ratios, and protocol trial designs that maximize contrast for hippocampal activity while minimizing those from other brain regions. While localizing activity to specific sub-structures within the
hippocampus has not been achieved, we provide recommendations for improving the reliability of such endeavors.