Experimental designs and processing strategies for fMRI studies involving overt verbal responses
Experimental designs and processing strategies for fMRI studies involving overt verbal responses
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DOI：
10.1016/j.neuroimage.2004.07.039
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发表时间：
2004-11-01
期刊：
影响因子：
5.7
通讯作者：
Bandettini, PA
中科院分区：
文献类型：
--
作者：
Birn, RM;Cox, RW;Bandettini, PA
在过去的几年里，事件相关范式越来越多地被用于涉及公开言语的任务中的功能定位。这些设计利用了快速运动引起的血流动力学信号变化和较慢的血流动力学信号变化之间的时间特性差异。这些设计的优化和分析所获取数据的最佳方法尚未得到充分探索。本研究的目的是调查各种设计和分析策略，最大限度地提高功能的检测，同时尽量减少任务引起的运动伪影。事件相关范式和阻塞范式都可以专门设计来满足这些目标。各种事件相关的和块的设计进行了比较，在模拟和实验中涉及明显的字阅读，在他们的能力，以检测功能和避免语音引起的运动伪影。任务和控制持续时间为10秒的一个块设计和事件相关的设计，最小刺激持续时间（SD）为5秒，平均刺激间隔（ISI）为10秒，发现最佳检测血氧水平依赖的信号变化，没有显着的运动伪影。忽略在讲话期间获取的图像可以帮助恢复特别受运动影响的区域中的功能，但大大降低了其他区域中的检测能力。由于运动引起的信号变化的可变性，使用刺激定时作为附加的回归量来对运动进行建模在实践中几乎没有益处。爱思唯尔公司出版
Event-related paradigms have been used increasingly in the past few years for the localization of function in tasks involving overt speech. These designs exploit the differences in the temporal characteristics between the rapid motion-induced and the slower hemodynamic signal changes. The optimization of these designs and the best way to analyze the acquired data has not yet been fully explored. The purpose of this study is to investigate various design and analysis strategies for maximizing the detection of function while minimizing task-induced motion artifacts. Both event-related and blocked paradigms can be specifically designed to meet these goals. Various event-related and blocked designs were compared both in simulation and in experiments involving overt word reading in their ability to detect function and to avoid speech-induced motion artifact. A blocked design with task and control durations of 10 s and an event-related design with a minimum stimulus duration (SD) of 5 s and an average interstimulus interval (ISI) of 10 s were found to optimally detect blood oxygenation leveldependent signal changes without significant motion artifact. Ignoring images acquired during the speech can help recover function in areas particularly affected by motion but substantially reduces the detection power in other regions. Using the stimulus timing as an additional regressor to model the motion offers little benefit in practice due to the variability of the motion-induced signal change. Published by Elsevier Inc.