Measurements of the temporal fMRI response of the human auditory cortex to trains of tones
Measurements of the temporal fMRI response of the human auditory cortex to trains of tones
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DOI：
10.1006/nimg.1998.0322
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发表时间：
1998-04-01
期刊：
影响因子：
5.7
通讯作者：
Gore, JC
中科院分区：
文献类型：
--
作者：
Robson, MD;Dorosz, JL;Gore, JC
平均单次试验（AST）允许以高时间（1 s）和空间（0.1 cm（3））分辨率测量功能磁共振成像（fMRI）对听觉刺激的反应。使用这种模式，我们研究了瞬态信号响应100毫秒的短纯音在列车之间的100毫秒和25.5秒的总持续时间。我们已经证明，对于6 s及更长的刺激序列，fMRI对这种听觉刺激的反应近似为线性，但是较短的刺激产生的信号比对较长刺激的反应所预期的要大。如果假设对每个刺激的自适应响应，则可以对这种非线性行为进行建模。为了研究功能磁共振成像实验中扫描仪噪声对听觉系统对音调反应的影响，还进行了一项使用新范式的研究。这项研究表明，在扫描仪梯度噪声存在下进行时，对700 ms音调刺激的时间响应被修改，修改是响应幅度的小但显著增加（P <0.05）。最后，检查了使用AST方法测量功能激活开始的能力。人们发现，借助计算机模拟，每秒一个图像的采样率足以区分时间响应。使用在这项研究中获得的数据，发作时间计算的听觉皮层，这些结果是一致的，与当前的功能激活模型。(C)北京：科学出版社.
Averaged single trials (AST) allowed the functional magnetic resonance imaging (fMRI) response to auditory stimuli to be measured at high temporal (1 s) and spatial (0.1 cm(3)) resolution. Using this paradigm we investigated the transient signal response to 100-ms tone bursts in trains of between 100 ms and 25.5 s in total duration. We have demonstrated that the fMRI response to such auditory stimuli is approximately linear for trains of 6 s and longer, but that shorter stimuli produce signals that are larger than might be expected from the response to the longer stimuli. This nonlinear behavior can be modeled if an adaptive response to each stimulus is assumed. A study using a novel paradigm was also performed in order to study the influence of scanner noise during fMRI experiments on the auditory system response to tones. This study demonstrated that the temporal response to 700-ms tone stimuli is modified when performed in the presence of scanner gradient noise, the modification being a small but significant increase (P < 0.05) in the magnitude of the response. Finally the ability to measure the onset of functional activation using the AST method was examined. It was found, with the aid of computer simulation that a sampling rate of one image per second is adequate to distinguish temporal responses. Using the data acquired in this study, onset times were calculated for the auditory cortex, and these results are consistent with current models of functional activation. (C) 1998 Academic Press.