CHARACTERIZING EVOKED HEMODYNAMICS WITH FMRI
CHARACTERIZING EVOKED HEMODYNAMICS WITH FMRI
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DOI：
10.1006/nimg.1995.1018
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发表时间：
1995-06-01
期刊：
影响因子：
5.7
通讯作者：
FRACKOWIAK, RSJ
中科院分区：
文献类型：
--
作者：
FRISTON, KJ;FRITH, CD;FRACKOWIAK, RSJ
我们描述了一般线性模型的实现，当这些反应的确切形式未知时，该模型有助于表征对感觉运动或认知处理的诱发血流动力学反应。这种方法的重要性在于，人们可以测试可能无法进行更传统分析的任务之间的差异响应。特别是，我们假设诱发反应具有早期和晚期成分，并且差异反应可能涉及（i）两个成分相同程度，如传统的“激活”或（ii）两个任务中早期和晚期成分的差异表达，如差异适应或与任务相关的差异（例如，需要和不需要持续注意）。使用这种方法，我们能够证明前扣带回在其反应方面区分需要和不需要持续注意力的两项运动任务。即使没有经典的“激活”（即，与两种条件相关的平均活性没有差异），也观察到了这种差异反应。建议这些演示结果表明有可能更多地利用快速功能磁共振成像技术提供的时间分辨率。 (C) 1995 学术出版社
We describe an implementation of the general linear model that facilitates the characterization of evoked hemodynamic responses to sensorimotor or cognitive processing when the exact form of these responses is not known. The importance of this approach is that one can test for differential responses among tasks that may elude more conventional analyses. In particular, we suppose that an evoked response has early and late components and that a differential response may involve (i) both components to the same degree, as in a conventional ''activation'' or (ii) differential expression of the early and late components in two tasks, as might be seen in differential adaptation, or differences associated with the tasks (e.g., requiring and not requiring sustained attention). Using this approach we were able to demonstrate that the anterior cingulate differentiates, in terms of its response, between two motor tasks that did and did not require sustained attention. This differential response was observed even though there was no classical ''activation'' (i.e., there was no difference in the mean activity associated with the two conditions). It is suggested that these demonstration results point to the possibility of making greater use of the temporal resolution afforded by fast fMRI techniques. (C) 1995 Academic Press, Inc.