聋人枕叶视皮层对频率刺激反应规律的事件相关fMRI研究

Study on the Visual Cortical Response to Stimulus Frequency in Deaf with Event Related fMRI

目的 :探讨聋人枕叶视皮层对视觉频率刺激的反应规律。材料和方法 :采用事件相关fMRI技术 ,对 8例聋人和正常人分别给予不同频率的刺激 ,通过MR采集其脑部数据 ,运用SMPM99统计软件进行处理分析。结果 :聋人与正常人的枕叶视皮层在不同频率刺激下均产生兴奋 ;随着频率的增加 ,聋人与正常人枕叶视皮层的兴奋区兴奋强度 (intensity)呈现先增加后下降并略有反弹的趋势 ,二者相似 ;聋人与正常人的最佳刺激频率分别为 4Hz和 6Hz。结论 :聋人与正常人的枕叶视皮层对频率刺激的基本反应规律是相似的 。

Purpose:To study the deaf and normal brain response various stimulus frequency rates using event related functional magnetic resonance imaging (ER fMRI), and to describe the rules of response and find the best stimulus frequency rate.Materials and Methods: Deaf subjects (n=8) and normal subjects (n=8) were stimulated by different frequency rates. The fMRI data were collected on GE 1.5 T Signa Horizon LX MRI system and analyzed by SPM99. Results: Responding to various stimulus frequency rates, significant activations were observed in occipital visual cortex in all deaf and normal subjects. For both deaf and normal subjects, the amplitude of the fMRI response increased with the stimulus frequency firstly, then declined slightly. The peaks for deaf and normal was 4Hz and 6Hz respectively. Conclusion:The brain response to visual stimulus frequency rates for deaf subjects is similar to that of normal subjects, but has some differences on the peak.