Temporal pattern of acoustic imaging noise asymmetrically modulates activation in the auditory cortex.
Temporal pattern of acoustic imaging noise asymmetrically modulates activation in the auditory cortex.
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DOI：
10.1016/j.heares.2015.09.017
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发表时间：
2016-01
期刊：
影响因子：
2.8
通讯作者：
Talavage TM
中科院分区：
文献类型：
--
作者：
Ranaweera RD;Kwon M;Hu S;Tamer GG Jr;Luh WM;Talavage TM
本研究探讨了成像相关声学噪声的时间模式对听觉皮层激活的半球特异性影响。成像体积和有效重复时间（TR）的独特组合所产生的噪声对应的五种成像噪声时间模式的血流动力学响应（hdr），使用超长（≥27.5s） TR的频闪事件相关范式来最小化内部采集效应。除了证实听觉皮层的fMRI反应不以线性方式表现外，还发现成像噪声的时间模式可以调节血流动力学反应的形状和空间范围，典型的非听觉区域对持续时间较长的噪声条件表现出反应。半球分析显示，右侧初级听觉皮层比左侧对与成像相关的噪音更敏感。在所有条件下，右侧初级听觉皮层的反应都明显更大。这种对成像相关声学噪声的不对称响应可能导致在使用短TR的采集方案中不同的基线激活水平，通过动态范围的限制，而不是由于神经元对刺激的处理差异，导致对预期声刺激的响应出现不对称。这些结果强调了在比较不同的fMRI研究结果时，特别是涉及声刺激的研究结果时，考虑噪声的时间模式的重要性。
This study investigated the hemisphere-specific effects of the temporal pattern of imaging related acoustic noise on auditory cortex activation. Hemodynamic responses (HDRs) to five temporal patterns of imaging noise corresponding to noise generated by unique combinations of imaging volume and effective repetition time (TR), were obtained using a stroboscopic event-related paradigm with extra-long (≥27.5s) TR to minimize inter-acquisition effects. In addition to confirmation that fMRI responses in auditory cortex do not behave in a linear manner, temporal patterns of imaging noise were found to modulate both the shape and spatial extent of hemodynamic responses, with classically non-auditory areas exhibiting responses to longer duration noise conditions. Hemispheric analysis revealed the right primary auditory cortex to be more sensitive than the left to the presence of imaging related acoustic noise. Right primary auditory cortex responses were significantly larger during all the conditions. This asymmetry of response to imaging related acoustic noise could lead to different baseline activation levels during acquisition schemes using short TR, inducing an observed asymmetry in the responses to an intended acoustic stimulus through limitations of dynamic range, rather than due to differences in neuronal processing of the stimulus. These results emphasize the importance of accounting for the temporal pattern of the acoustic noise when comparing findings across different fMRI studies, especially those involving acoustic stimulation.