The Effect of Time Pressure and Task Difficulty on Human Search

In order to study the effect of time pressure and task difficulty on human search performance, an experimental study was conducted. Thirteen people participated in the experiment. The time pressure is changed by changing the presentation time of the target information on the display. The task difficulty is changed by changing the number of the target information displayed on the computer display. Subjects' reaction time (RT), accuracy rate and eye movement data were recorded during the experiment. The results show that the subjects' reaction time decrease and accuracy rate increase. The subjects' reaction time increased and accuracy rate decreased when the task difficulty increase. Eye movement data also changed with the change of time pressure and task difficulty. When time pressure increased, the pupil diameter increased, number of fixation points decreased, fixation frequency increased and average fixation time decreased. Pupil diameter increased when task difficulty increase. So the conclusion could be made that eye movement behavior and search performance change with the change of task difficulty and time pressure. During Human-machine Interface Design, the task difficulty and time pressure need to be scientifically designed to optimize the performance of the operator.