Center for Functional Magnetic Resonance Imaging, University of California San Diego, La Jolla, CA 92093-0677, USA.
Neuroimage. 2012 Aug 15;62(2):1157-62. doi: 10.1016/j.neuroimage.2011.10.008. Epub 2011 Oct 21.
The diversity of experimental designs that can be used with functional magnetic resonance imaging (fMRI) has played a key role in its widespread application to studies of human cognition. This flexibility is possible because the fMRI response to external stimuli is remarkably well approximated as the response of a linear time variant system. The experimental demonstration of this property provided the foundation for the development of event-related designs, in which the fMRI response is modeled as the linear summation of the hemodynamic response to discrete events. Building upon prior work from the fields of engineering, neuroscience, and statistics, researchers in the field have created a rich collection of event-related designs and developed a rigorous theoretical framework for characterizing and optimizing the performance of designs. Ongoing challenges include the optimization of designs in the presence of experimental constraints and the development of more time-efficient optimization algorithms.
功能磁共振成像（fMRI）可采用的实验设计种类繁多，这对其在人类认知研究中的广泛应用起到了关键作用。这种灵活性成为可能，是因为外部刺激的 fMRI 反应可以很好地近似为线性时变系统的反应。该特性的实验证明为事件相关设计的发展提供了基础，其中 fMRI 反应被建模为离散事件的血流动力学反应的线性总和。在工程、神经科学和统计学等领域的前期工作基础上，该领域的研究人员创造了丰富的事件相关设计集合，并为设计的特征描述和性能优化开发了严格的理论框架。当前的挑战包括在存在实验限制的情况下优化设计，以及开发更高效的优化算法。
