与识别声音熟悉性有关脑区的功能核磁共振成像研究

Neural Substrates for Voice Familiarity: a fMRI Study

目的利用组块设计功能核磁共振成像技术研究声音熟悉性的神经网络基础。方法利用1.5T核磁共振成像系统对13名中国汉族成年健康男性受试者进行扫描,同时给予事先录制编辑好的言语性声音刺激,并通过反馈系统记录反应结果。应用SPM99软件处理分析数据,获得脑区激活图和局部血氧水平反应曲线,并分析受试者行为学反应结果之间的相关性及行为学反应结果与“熟悉”声音激活脑区之间的相关性。结果与接受“不熟悉”声音刺激相比,受试者在接受“熟悉”声音刺激时,下列脑区显著激活后扣带回、丘脑、右颞中回和右前额中回。相应的受试者在接受“不熟悉”声音刺激时,相对于接受“熟悉”声音刺激,左楔前叶、枕叶和楔叶显著激活。受试者对“熟悉”声音的判断正确率与对“熟悉”声音识别的平均反应时间呈负相关(r=-0.60,P=0.03);而辨别“熟悉”声音的平均反应时间与丘脑的激活程度呈正相关(r=0.59,P=0.03)。结论后扣带回、丘脑、右颞中回及右前额中回可能是辨别“熟悉”声音神经网络基础的重要组成部分,并且辨别“熟悉”声音与辨别“不熟悉”声音之间可能存在不同的脑功能基础。

Objective： To identify neural correlates for the recognition of familiar verbal voices by measuring regional blood oxygen level-dependent （BOLD） signal by functional magnetic resonance imaging （fMRI） . Methods： Thirteen Chinese health male subjects （ mean age 26. 1 years, SD = 2.9years） participated in the study. All subjects were right-handed and Han nationality. The subjects listened to familiar （subjects＇friends） and unfamiliar voices when functional scanning. Functional data were acquired using a 1.5T MRI （GE Systems, USA）, and were analyzed using statistical parametric mapping 99 （ SPM99 ） . A fixed-effects model was employed to assess the difference in BOLD response between familiarity＇ and ‘unfamiliarity＇conditions （P 〈 0. 001, uncorrected for multiple comparisons, extent threshold more than 10 voxels） . The behavioral results were recorded by Presentation software. Furthermore, we correlated an estimate of the magnitude of the BOLD response with performance on behavior task cross subjects. Results： The posterior cingnlate gyrus, thalamus, right medial temporal gyrus and right medial prefrontal gyrus were more activated by familiar task than unfamiliar task. The mean reaction time to familiar voices correlated positively with the activation degree of thalamus when subjects＇recognising familiar voice. Conclusions： The posterior cingnlate gyrus, thalamus, right medial temporal gyrus and right medial prefrontal gyrus play very important roles in recognition of familiar verbal voices.