Ulmer J L, Biswal B B, Yetkin F Z, Mark L P, Mathews V P, Prost R W, Estkowski L D, McAuliffe T L, Haughton V M, Daniels D L
Department of Radiology, Medical College of Wisconsin, Milwaukee, USA.
J Comput Assist Tomogr. 1998 Jan-Feb;22(1):111-9. doi: 10.1097/00004728-199801000-00021.
Our goal was to determine the distribution of auditory and language cortex activation in response to acoustic echo planar scanner noise with functional MRI (fMRI).
Acoustic scanner noise and spoken text, reproduced on high output cassette tape, were separately delivered at equivalent intensities to six normal hearing adult volunteers through earphones during fMRI data acquisition. In nine other subjects, taped scanner noise was delivered in five successive iterations of the task to assess the consistency of cortical activation to the noise stimulus. Gyri of the auditory and language system were divided into 10 different subregions for analysis of cortical activation. The number of activated pixels and proportion of volunteers activating each cortical subregion were determined using a cross-correlation analysis.
Cortical activation to taped acoustic scanner noise was present within the transverse temporal gyrus (primary auditory cortex) in all subjects, but activation was highly variable between subjects in auditory association and language relevant cortex. Auditory association cortex activation was seen in the planum polari, planum temporali, and middle temporal gyrus/superior temporal sulcus regions in one-half to two-thirds of the volunteers. There was no significant difference in the distribution of cortical activation within individual subjects across five successive iterations of the scanner noise task. Listening to spoken text consistently activated primary and association auditory cortex bilaterally as well as language relevant cortex in some cases. The mean number of activated pixels was significantly greater for text listening than acoustic scanner noise in auditory association and language relevant cortical subregions (p < 0.01), although the distribution of activity was similar between the two tasks.
This preliminary investigation suggests that the complex sounds produced by the echo planar pulse sequence can activate relatively large regions of auditory and language cortex bilaterally, with the extent of activation outside the primary auditory cortex being variable between subjects. However, the distribution of activation within individual subjects was relatively constant across several iterations of the scanner noise stimulus.
我们的目标是通过功能磁共振成像（fMRI）确定听觉和语言皮层对声学回波平面扫描仪噪声的激活分布。
在fMRI数据采集期间，通过耳机将高输出盒式磁带上重现的声学扫描仪噪声和口语分别以等效强度传递给六名听力正常的成年志愿者。在另外九名受试者中，在五次连续的任务迭代中传递录制的扫描仪噪声，以评估皮层对噪声刺激激活的一致性。将听觉和语言系统的脑回分为10个不同的子区域，用于分析皮层激活。使用互相关分析确定激活像素的数量和激活每个皮层子区域的志愿者比例。
所有受试者的颞横回（初级听觉皮层）内均出现对录制的声学扫描仪噪声的皮层激活，但听觉联合区和语言相关皮层的受试者间激活差异很大。在一半至三分之二的志愿者中，在颞极平面、颞平面和颞中回/颞上沟区域观察到听觉联合皮层激活。在扫描仪噪声任务的五次连续迭代中，个体受试者内皮层激活的分布没有显著差异。听口语在某些情况下会持续双侧激活初级和联合听觉皮层以及语言相关皮层。在听觉联合和语言相关皮层子区域，听口语时激活像素的平均数量显著多于声学扫描仪噪声（p < 0.01），尽管两项任务的活动分布相似。
这项初步研究表明，回波平面脉冲序列产生的复杂声音可双侧激活相对较大区域的听觉和语言皮层，初级听觉皮层外的激活程度在受试者间存在差异。然而，在扫描仪噪声刺激的几次迭代中，个体受试者内的激活分布相对恒定。
