VDT阅读作业脑力负荷的评价

Evaluation of Mental Workload during Reading Performance on VDT

目的探讨采用主观评分法、主任务评定法、心理生理学评定法3种脑力负荷评定方法评价视频显示终端(visual display terminal,VDT)阅读作业脑力负荷的可行性。方法14名大学生(为志愿受试者)在计算机上阅读短文各自15,30,60 min,分别为A,B,C组,测定分析受试者完成3组阅读时的库柏-哈柏(Cooper-Harper Scale)量表评分、正确率、阅读速度、阅读效率、心率变异性、瞳孔直径变化率、眨眼率等脑力负荷评定指标。结果随着阅读时间的延长,库柏-哈柏量表评分分值、正确率、阅读速度,瞳孔直径,眨眼率的差异无显著性;C组与A组相比,阅读效率下降;阅读与休息时相比,眨眼率减少;心率变异性(heart rate variability,HRV)总的频域值(TP)、极低频成分(VLF)、低频成分(LF)、高频成分(HF)、平均正常RR间期的标准差(SDNN)值升高,但3组之间比较,差异无显著性。结论60 min阅读作业在生理和主观评估对机体有一定的影响。主观评分法、主任务评定法、心理生理学评定法3种脑力负荷评定方法的结论基本一致,能在一定程度上反映阅读任务的脑力负荷信息,可作为脑力负荷评价某个方面的指标。

Objective To investigation the feasibility of using subjective rate, primary task evaluation and psychophysiology evaluation methods to evaluate the mental workload during reading performance on VDT. Methods 14 student volunteers as the subjects were divided into three group, i.e. group A, B, and C, and were requested to read short papers and answer questions on the computer for 15, 30 and 60 minutes. Parameters including Cooper Harper scale score, correct rate, reading speed, reading efficiency, heart rate variability, pupil size, and blink rate were determined. Results As the reading time extended, the Cooper-Harper scale score, the accuracy, the reading speed, pupil size and blink rate were not significantly different among three groups. Reading efficiency of group C decreased compared to group A. In comparison with the rest time, the values of TP, VLF, LF, HF, SDNN increased remarkably, the value of TB decreased; however, the differences were not significant among three groups. Conclusions Reading on VDT shows certain adverse effects on participants＇ mental workload in 60 minutes. Three mental workload evaluation methods could be used to assess the mental workload certain extent, and could provide some mental workload information during reading performance on VDT in evaluation indicators.