视觉专家技能化脑加工机制的功能磁共振研究  

Functional magnetic resonance imaging research on brain processing mechanism of visual expertise

作　　者：李胜辉[1] 李敏[1] 姜庆军[1] 李勃[1] 杨晓[1] 李理[1] 孙钢[1] 

机构地区：[1]济南军区总医院医学影像科,250031

出　　处：《中华消化病与影像杂志（电子版）》2014年第1期20-23,共4页Chinese Journal of Digestion and Medical Imageology(Electronic Edition)

摘　　要：目的研究专家技能化对胸部平片视觉识别脑加工机制的影响,进一步揭示专家化技能影响物体识别的机制。方法对26名志愿者进行功能磁共振(fMRI)研究,其中高年资放射科医师(主治医师以上)11名(高年资放射医师组),非放射专业实习学员15名(非放射专业组)。实验采用组块设计方案。任务状态组块与控制状态组块采用的刺激分别为面孔图片与物体(花)图片以及胸部平片与物体(花)图片,任务组块与控制组块交替进行,其间无休息模块。每位受试者均进行8个任务组块与控制组块的刺激,每个组块内呈现9幅图片,同时,每个模块中出现一幅与目标图片一致的目标,要求被试者发现相同图片时按键,记录其反应时间与判断正确率并进行比较。结果非放射专业组胸片判断准确率为(23.3±8.0)%,反应时间为(0.78±0.11)s;高年资放射医师组胸片判断准确率为(87.5±9.7)%,反应时间为(0.36±0.06)s。高年资放射医师组与非放射专业组相比胸片判断准确率提高,反应时间缩短,且差异均有统计学意义(t=221,P<0.001;t=198,P<0.001)。非放射专业组中,面孔-物体均引起"梭状回面孔区"(FFA)激活,激活峰值为(0.26±0.04)%,胸片-物体FFA无激活。高年资放射医师组中,面孔-物体与胸片-物体FFA激活峰值差异无统计学意义[(0.27±0.02)%vs(0.26±0.02)%,t=-1.9,P=0.08]。高年资放射医师组右侧梭状回FFA激活峰值高于左侧梭状回,且差异有统计学意义[(0.26±0.02)%vs(0.16±0.06)%,t=6.1,P<0.001]。胸片-物体FFA激活峰值与反应时间呈负相关(r=-0.71,P=0.01),与判断准率呈正相关(r=0.61,P=0.048)。结论随着专家技能化的增加,胸部平片亦可形成类似面孔识别的加工机制,产生右侧梭状回明显激活;出现专家技能化时,物体识别由局部加工变为整体加工,进而提升加工效率。Objective To study the influence of expertise on brain processing mechanism of chest X-ray films visual identification , and further reveal that how the expertise affects object recognition . Methods Twenty-six participants （ volunteers ） underwent functional magnetic resonance imaging （ fMRI ） examination,including 11 experienced radiologists （ experienced radiologists group ） and 15 interns （ interns group） .The study was designed as block protocol .The stimulus of task state blocks and control state blocks were defined as faces-flowers and chest films-flowers respectively .These two kinds of blocks went on alternately and no rest blocks were present during the whole procedure .Participants underwent 8 task state blocks and 8 control state blocks respectively .Nine images were shown per block .When an image turned up which was consistent with the target image , participants were instructed to press a button .The reaction time and correct ratio were recorded and compared .Results The accuracy of interns group was （ 23.3 ＆#177;8.0 ）%and the reaction time was （0.78 ＆#177;0.11 ） s,while the experienced radiologists group showed a higher accuracy [（87.5 ＆#177;9.7）%] and a shorter reaction time [（0.36 ＆#177;0.06）s],and there were significant differences between the two groups in terms of the accuracy and the reaction time （t =221,P ＆lt;0.001;t =198,P ＆lt;0.001）.In interns group,all the fusiform face area（FFA）were activated [amplitude：（0.26 ＆#177;0.04）%] when faces-objects were presented ,while there was no activity in FFA when chest films-objects were shown . The difference of activity amplitude in FFA between faces-objects and chest films-objects was not significant in experienced radiologists group [（0.27 ＆#177;0.02）%vs （0.26 ＆#177;0.02）%;t=-1.9,P=0.08].The FFA＆amp;nbsp;amplitude of right fusiform gyrus was higher than the left side significantly [ （ 0.26 ＆#177;0.02 ）% vs （ 0.16 ＆#177; 0.06）%,t=6.1,P＆lt;0.001].The activity ampli

关 键 词：视觉差异 认知 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]