BASELINES FOR FMRI STUDIES OF LANGUAGE

使用成像技术来观察大脑功能是一种相对 新的研究领域，因此方法的变化（例如，选择 基线和任务说明）可以解释观察到的差异 研究之间的结果。这种方法上的差异使其 很难得出可靠的、一致的结论。如果我们 是为了更深入地了解大脑/行为的关系，那么这些 应解决方法上的不一致问题。这个目标 研究的目的是制定一个健全的实验方案，供今后使用 研究语言处理，特别是语音处理。 因此，拟议的研究试图1）确定哪条基线 程序产生最稳定的激活模式，2）确定 研究结果之间的差异是否部分 归因于所用基线程序的差异，3） 确定用于检查语音处理的两个任务 （音素辨别和音素监测）激活相似的大脑 这意味着它们需要使用类似的方面， 语音处理，4）确定是否与功能区 特异性受到认知过程的影响，以及5） 确定信号强度降低的区域是否与 信号强度增加的区域意味着抑制（减少 在氧消耗不抑制）的某些领域可能是必要的， 让其他领域活跃起来。此外，大多数功能 先前进行的研究使用PET来获得图像数据。当前 研究将使用4.1T磁共振系统进行成像。的 4.1T MR系统也允许更好的信噪比（SNR） 与PET和PET相比， 传统的1.5T系统分辨率和SNR的改进提供了 有机会获得比可能更清晰的大脑激活图片 与其他成像系统，从而提高能力， 区分激活任务期间创建的激活和 基线任务。

The use of imaging techniques to observe brain function is a relatively new research area, so variations in methodology (e.g., choice of baseline, and task instructions) may account for discrepancies observed in results between studies. This variation in methodology make it difficult to draw reliable, consistent conclusions across studies. If we are to gain greater insight into brain/behavior relationships, then these methodological inconsistencies should be addressed. The goal of this study is to develop a sound experimental protocol to be used in future studies of language processing, particularly phonological processing. Therefore, the proposed research attempts to 1) determine which baseline procedure produces the most stable activation pattern, 2) determine whether the discrepancies in the results across studies is partially attributed to differences in the baseline procedures employed, 3) determine if the two tasks used to examine phonological processing (phoneme discrimination and phoneme monitoring) activate similar brain areas implying that they require the use of similar aspects of phonological processing, 4) determine if areas with functional specificity are affected by the addition of cognitive processes, and 5) determine whether areas of decreased signal intensity are correlated to areas of increased signal intensity implying that suppression (a decrease in oxygen consumption not inhibition) of some areas may be necessary in order for other areas to be active. Also, the majority of the functional studies previously performed used PET to obtain image data. The current study will use a 4.1T magnetic resonance system to perform imaging. The 4.1T MR system allows for much better signal to noise ratio (SNR) as well as improved spatial and temporal resolution compared to both PET and conventional 1.5T systems. Improvements in resolution and SNR provide the opportunity to obtain a clearer picture of brain activation than possible with other imaging systems thereby, improving the ability to differentiate between activation created during the activation task and the baseline task.