摘要
目的探讨脑认知中选择性注意对感知处理过程的影响,重点观察不同视觉注意状态对视觉中枢的影响。方法应用3.0T MR仪对9名正常志愿者进行脑功能成像数据采集,应用经典组块设计视觉刺激,通过单纯改变注视点颜色刺激并要求被试实时记录变化情况,来改变被试注意状态。采用SPM5软件对激活区进行个体及组分析处理,对图像处理中不同平滑值所得结果进行分析,并对激活位置、范围进行对比,观察正常人视觉中枢激活的变化情况。结果在持续注意状态下视皮层以外区域脑激活显著减少,并在受试者间具有较好的可重复性。结论持续注意状态可显著减少视皮层之外的假阳性激活,因此建议在fMRI试验的不同任务中,控制受试者注意状态,正确分析所获得结果中可能存在的混淆因素。
Objective To evaluate the influence of selective attention on perceptual processing of visual cortex,even for apparently low-level visual stimuli as different attentional input.Methods Nine healthy volunteers were enrolled,whose attention were directed towards random transient color changes of the fixation point,and the responses were recorded simultaneously.The data were collected with block designed program on 3.0T MR system and analyzed with SPM5.Results False positive activations outside the known visual areas in the attention-controlled condition significantly reduced,and the results were reproducible among the subjects.Conclusion The false positive activations can be reduced in the attention-controlled condition by the changes of visual input.Therefore,it is highly recommended to control subject's attention during different conditions of fMRI experiment or to treat such effects as possible confounds.
出处
《中国医学影像技术》
CSCD
北大核心
2010年第8期1437-1440,共4页
Chinese Journal of Medical Imaging Technology
关键词
注意力
视皮质
磁共振成像
Attention
Visual cortex
Magnetic resonance imaging