摘要
目的 利用注意网络测试（ANT）及事件相关fMRI研究热应力对人类视觉注意网络的影响.方法 30名健康受试者采用随机数字表随机分为试验组与对照组,每组15名.分别在高温（50℃、40％相对湿度）和常温（20℃、40％相对湿度）环境下进行注意网络测试相关fMRI.采用一般线性模型分析2组受试者注意网络的3个子网络（警觉、定向和执行控制网络）行为学效应值有无差异;利用统计参数图8,进行独立样本t检验,采用AlphaSim校正,分别得到2组受试者注意网络3个子网络统计参数图,然后再进行独立样本t检验,得到2组差异统计参数图.结果 试验组有3名受试者数据因头动过大而被剔除.行为学结果显示,热应力使注意网络的执行功能效应值增大[试验组（82.56±20.89）ms,对照组（58.55±8.96）ms,F=16.683,P＜0.01],而警觉功能和定向功能未受影响（P值均＞0.05）.fMRI结果显示：（1）热应力增强了警觉网络中右侧额上回的激活（体素39,t=3.02,P＜0.01）,而抑制了右侧枕中回、左侧顶下小叶和左侧山顶的激活（体素分别为49、86、97,t值分别为-2.86、-3.69、-2.72,P值均＜0.01）;（2）热应力增强了定向网络中右侧颞中回、左侧颞上回的激活（体素分别为29、58,t值分别为5.00、4.57,P值均＜0.01）,而抑制了左侧额下回、右侧额中回、右侧额上回、左侧枕中回、左侧中央后回、左侧额中回等脑区的激活（体素为29～85,t值为-5.40～-2.61,P值均＜0.01）;（3）热应力增强了执行控制网络中前额叶背外侧的激活（左右两侧激活体素分别为35、58,t值分别为2.99、3.10,P值均＜0.01）,但对前扣带回激活没有影响.结论 热应力损伤了执行控制功能,尤其是解决冲突的能力;大脑通过不同的神经元激活模式克服了热应力对警觉和定向功能的影响.
Objective To investigate the effect of passive hyperthermia on attention network with the event-related functional magnetic resonance imaging （fMRI）.Methods Thirty participants were randomly divided into 2 groups （hyperthermia group and control group）.They performed the attention network test （ANT） with event-related fMRI in a hot （50℃ and 40% relative humidity） or neutral （20℃ and 40% relative humidity） environment,respectively.The network scores were analyzed using a multivariate analysis （MANOVA） within the GLM package,with group as the fixed factor.Univariate posthoc tests with Tukey corrections for multiple comparisons were used to investigate group differences on each of the three networks.The fMRI data were realigned,normalized and then smoothed with 6 mm FWHM kernel.The fMRI results of the three attention networks were compared between the hyperthermia and the control groups using a two-sample t-test respectively with SPM8.The statistical maps were generated with an integrated threshold at a corrected level of P 〈 0.05.Results The behavioral results showed that heat stress enlarged the scores of the executive network [（82.56 ± 20.89） ms vs （58.55 ± 8.96） ms,F =16.683,P 〈0.01],but showed no effect on the alerting and orienting networks （P 〉 0.05）.The fMRI results showed that：（i） heat stress enhanced the activity in the right superior frontal gyrus （voxel number =39,t =3.02,P 〈 0.01） and depressed the activity in the right middle occipital gyrus,left inferior parietal lobule and left culmen （voxelnumber=49,86,97; t=-2.86,-3.69,-2.72; and P〈0.01,respectively） in the alerting network,（ii） heat stress enhanced the activity in the temporal lobe （voxel number =29,58; t =5.00,4.57; and P 〈 0.01,respectively） and depressed the activity in the frontal lobe,parietal lobe and occipital lobe （voxel number =29-85 ; t =-5.4-2.61 ; and P 〈 0.0l,respectively） in the orienting network,and （iii） heat stress enhanced the activity in the dorsolateral prefrontal cortex （voxel number =35,58; t =2.99,3.10; and P 〈0.01 for the left or right dorsolateral prefrontal cortex,respectively） but not affected the activity in the anterior eingulate.Conclusions Heat stress impaired the executive function,especially the efficiency of resolving conflict.The negative effects of heat stress on alerting and orienting were overcome by variant regional brain activation.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2013年第12期1092-1097,共6页
Chinese Journal of Radiology
关键词
热
注意力
磁共振成像
Heat
Attention
Magnetic resonance imaging
