听觉功能MRI研究的实验设计

Experiment design of auditory functional MRI

目的探讨听觉fMRI研究的有效数据采集方式。方法对13例健康年轻受试者分别采用纯音及调幅音两种听觉刺激条件,刺激分别采用组块和事件相关设计进行听觉呈现,以比较连续及稀疏两种采集方式下听觉皮层的fMRI响应,运用SPM2软件进行数据分析和脑功能区定位,并分析两种不同实验数据采集方式下听觉皮层激活的差异。结果调幅声较纯音更易激发听觉皮层的激活;两种刺激条件下,稀疏采集时听觉皮层的fMRI响应明显多于连续采集,比较听觉皮层各区,以初级听觉皮层fMRI响应为著。结论调幅音是听觉fMRI研究中的合适刺激;稀疏采集方式有助于克服环境噪声的负面影响,结合物理衰减方法,可实现听觉功能的fMRI研究。

Objective To probe the available data acquisition in auditory functional MRI. Methods Functional MR images were acquired in 13 healthy young subjects. The tasks were pure tone and amplitude modulation tone. Block and event-related design were both applied in all subjects. SPM2 was used to process data and localize functional areas of brain. The differences between the two experiments design were analyzed. Results Amplitude modulation tone generated greater activation in auditory cortex than pure tone. Under the two kinds of stimulation, activation of auditory cortex in sparse acquisition was notably greater than that in continuous imaging, especially in primary auditory cortex. Conclusion Amplitude modulation tone can be used as a kind of suitable task stimulation in auditory functional MRI. Sparse temporal sampling in auditory functional MRI can overcome adverse effect of ambient noise. Auditory functional MRI can be effectively obtained by combining sparse imaging and physical attenuation method.