快速序列视觉呈现字符流中后继干扰物对注意瞬脱的影响(英文)

Effect of subsequent distractors in rapid serial visual presentation stream on the attentional blink

背景:注意瞬脱强调了快速序列视觉呈现字符流中紧跟在靶之后的干扰物和位于靶之前的引导干扰物对于注意瞬脱产生的重要性,但位于第2靶(T2)之后的后继(除了紧跟的那个)干扰物作用的报道并不多见。目的:验证快速序列视觉呈现中T2之后的后继干扰物对注意瞬脱的作用。设计:随机对照观察。单位:中南民族大学认知科学实验室。对象:选择25名中南民族大学本科学生,年龄18～21岁,平均19岁。所有学生均无神经精神性疾病,视力或矫正视力正常,并对检测项目知情同意。将受试对象分为实验组(n=14)及对照组(n=11),两组年龄、性别构成差异无统计学意义(P>0.05)。方法:实验于2007-01/04在中南民族大学认知科学实验室完成。①实验干预:刺激为由数字干扰物和2个字母靶组成的快速序列视觉呈现字符流。②实验分组:实验组参与去除条件实验,对照组参与保留条件实验。③结果分析:采用单因素方差分析评估同组数据的差异显著性,t检验用于比较两组之间的数据。主要观察指标:不同条件下两组受试对象对第1靶(T1)和第2靶(T2)的正确识别率。结果:纳入受试对象25名均进入结果分析。①保留条件下正确识别率:第1靶在不同间隔条件下的正确识别率为94.6%。对照组T2正确识别率在间隔1时高(92.7%),在间隔2时明显下降(79.8%),随后随着间隔增加而持续提高,间隔效应显著[F(4,40)=10.98,P<0.01]。②去除条件下正确识别率:第1靶在不同间隔条件下的正确识别率为96.2%。实验组T2报告正确率在间隔1时高(94.4%),在间隔2时降低(84.4%),随后在间隔3时提高(91.1%),然而在间隔5和间隔7时又明显下降(分别为44.9和43.9%)。间隔效应显著[F(4,52)=224.0,P<0.01]。③两种条件下结果的比较:与保留条件下的T2正确率相比,去除条件下的T2正确率在间隔5和间隔7时显著降低[t(23)=34.44,42.56,P<0.01];但在间隔1,2,3时差异无显著性(P>0.05)。结论:T2之后的后继干扰物的缺失通过使被试的注意状态引入偏差而导致长间隔时的T2正确率下降到不同寻常的低水平。

BACKGROUND：Researches on attentional blink （AB） emphasized the importance of the distractors directly following targets and that of the leading distractors in rapid serial visual presentation （RSVP） streams in the production of the AB,but little has been mentioned about the subsequent distractors after the second target （except the one in direct succession to it）. OBJECTIVE： To investigate the effect of subsequent distractors in RSVP stream on AB after the second target （T2）. DESIGN： A randomized and controlled study. SETTING： Laboratory of Cognitive Science, South-central University for Nationalities. PARTICIPANTS： Twenty-five undergraduates aging 18-21 years with the mean age of 19 years were selected from South-central University for Nationalities. All undergraduates participated in the experiment did not have nervous mental diseases but had normal sight or corrected visual acuity; meanwhile, all of them provided the confirmed consent. The subjects were divided into experimental group （n =14） and control group （n =11）. There were no significant differences between the two groups in age and sex （P 〉 0.05）. METHODS： The experiment was carried out in the Laboratory of Cognitive Science, South-central University for Nationalities from January to April 2007. ① Experimental intervention： The stimuli were RSVP streams consisted of digit distractors and two letter targets （T1 and T2）. ② Experimental grouping： The experimental group participated in the omitted condition and the control group participated in the preserved condition. ③ Experimental analysis： One-way ANOVA was used to evaluate the data for statistically significant difference in the same group, and t test was used to compare data between two groups. MAIN OUTCOME MEASURES： Report accuracy of T1 and T2. RESULTS： A total of 25 subjects were involved in the final analysis. ① Report accuracy in the preserved condition：Correct identification of the first target, averaged across all lags, was 94.6%. The percentages of correct identification of the second target as a function of lag was high at Lag1 （92.7%）, dropped dramatically at Lag2 （79.8%）, then kept improving with increase of lag, revealing a significant effect of lag [F（4,40） = 10.98, P〈 0.01]. ② Report accuracy in the omitted condition： Correct identification of the first target T1, averaged across all lags, was 96.2%. The percentages of correct identification of the second target as a function of lag, T2 report was high at Lag1 （94.4%）, decreased at Lag2（84.4%）, then improved at Lag3 （91.1%）, but dropped remarkably again at Lag5 and Lag7 （44.9 vs. 43.9%）, revealing a significant effect of lag [F （4,52） = 224.0, P 〈 0.01]. ③ Comparison of the results in two conditions： T2 accuracy in the omitted condition was significantly lower than that in the preserved condition at Lag5 [t （23）=34.44, P 〈 0.01], and Lag7 [t （23）=42.56, P 〈 0.01], but did not differ from each other at Lag1 [t （23）=0.65, P 〉 0.05], at Lag2 [t （23）=1.04, P 〉0.05], and at Lag3 [t （23）=0.64, P 〉 0.05]. CONCLUSION： The absence of subsequent distractors after T2 can introduce a bias on the attentional status of subjects to bring the T2 accuracy down to unusual low level at long lags.