前注意视觉皮层脑功能磁共振成像

Functional magnetic resonance imaging of preattentional visual cortex

目的探讨前注意视觉皮层的非注意视觉偏差刺激自动加工脑功能解剖的分布及意义。方法对20名健康右利手男性,采用经典oddball被动范式给予非注意视觉刺激,标准刺激为红色方块,概率为80%,偏差刺激为绿色方块,概率为20%,观察功能MRI影像学表现。结果最终分析15名被试,fMRI检查前、中、后的按键正确率均≥95%,反应时间差异无统计学意义(P=0.470)。fMRI显示右侧梭状回(枕颞内侧回)、右侧部分颞叶、枕叶及海马旁回,左侧枕叶,双侧额上回、双侧额中回及左侧中央前回/后回脑激活区BOLD信号在偏差刺激出现后明显升高。结论 fMRI可以清楚显示前注意视觉皮层功能解剖分布,为临床诊断前注意视觉皮层受损情况提供更加直观的检查方式,为疾病研究提供相应的参考信息。

Objective To explore the brain anatomical distribution and significance of the preattentional visual cortex during the automatic processing for visual deviant stimulus. Methods Totally 20 healthy right-handed men underwent visual deviant stimulus using classical oddball passive paradigm. The standard stimulus presented as red square, with the probability of 80%, while the deviation of the stimulus presented as green square, with the probability of 20%, and then the signals of fMRI were observed. Re- suits A total of 15 subjects were included in the final analysis. The button accuracies before, during and after the fMRI examina- tion were no less than 95%, and there were no statistically significant differences in reaction time （P=0. 470）. While fMRI re- vealed statistical significantly increased BOLD signals in the right {usiform gyrus （occipital temporal medial gyrus）, part of the right temporal lobe, occipital lobe and parahippocampal gyms, the left occipital lobe, bilateral superior and middle frontal gyrus and left anterior/posterior central gyrus. Conclusion fMRI can be used to reveal the anatomical distribution of the preattentional visual cor- tex clearly and provide a more specific inspection method for the clinical diagnosis of preattentional visual cortex damage, as well as reference for the corresponding disease research.