视觉记忆型次任务对驾驶绩效及安全的影响

为研究视觉记忆型次任务对驾驶绩效及安全的影响，采用对未知内容的记忆任务和对已知内容的再认任务分别表征工作记忆和长时记忆过程，构建多组不同难度的次任务，基于标准换道试验环境LCT进行双任务研究。提取并分析驾驶人执行不同任务时车道保持、换道控制等指标的差异以及次任务绩效，基于主客观数据构建综合评判模型。结果表明:双任务驾驶条件下，车辆平均路径偏差、方向盘平均转向角、车道偏移次数指标增大，正确换道比例减小，感知负荷增大，总绩效下降。困难工作记忆组与简单工作记忆组相比，随着任务难度增大，换道控制绩效下降，感知负荷增大，总绩效下降36.1%；困难再认组与工作记忆组相比，车道保持绩效、换道控制绩效提高，感知负荷下降，总绩效提高50%；简单再认组与工作记忆组相比，总绩效变化不大；困难工作记忆组综合绩效最低。上述结果说明:随着次任务难度增大，总绩效下降，但将对未知内容的工作记忆过程转化为对已知内容的再认过程时，总绩效明显提升，这一特点在任务难度较大时更为显著。

Influence of visual memory secondary task on driving performance and safety

In order to study the influence of visual memory secondary task on driving performance and safety, the memory task for unknown contents and recognition task for given contents were employed separately to represent the working memory process and long-term memory process. Multiple groups of secondary task with different difficulties were constructed, and the dual-task research was conducted based on the standard environment of lane change test (LCT). The difference of lane keeping, lane change control and other indexes and the performance of secondary task for drivers when executing different tasks were extracted and analyzed, and a comprehensive evalu-ation model was constructed based on the subjective and objective data. The results showed that for dual tasks driving, the average path deviation of vehicle, the average steering angle of steering wheel and the lane departure times increased, the percentage of correct lane change decreased, the sensory load increased, and the overall per-formance decreased. Compared with the simple working memory group, with the increasing tasks difficulty of difficult working memory group, the performance of lane change control decreased, the sensory load increased, and the overall performance decreased by 36.1%. Compared with the difficult working memory group, the performance of lane keeping and lane change control increased, the sensory load decreased, and the overall performance increased by 50% for the difficult recognition group. The overall performance of simple recognition group had little change with that of the simple working memory group, and the overall performance of the difficult working memory group was the lowest. It showed that with the increase of difficulty for secondary task, the overall performance will decrease, but the overall performance improves significantly when the working memory process for unknown contents is converted to recognition process for given contents, which is more significant when the task appears to be more difficult.