Abstract
Promoting system automation provide increased safety. However, there is concern that reduced human-system interaction may result in decreased arousal level and loss of the ability to perform. Thus, maintaining adequate arousal level in safety-critical operations is one of most important issues. Conventional approaches to maintaining arousal level are mainly based on external stimulation, but these can be accompanied by discomfort. In our previous study, as a new option to add to conventional methods, we proposed the method by inducing intrinsic motivation through voice prompts, and the proposed method has larger effect in maintaining arousal level than a method using voice of general driving-related information. However, the difference in the intensity of the effect on maintaining arousal level compared to existing methods has not been clarified. Thus, we compared the effectiveness of the method of inducing intrinsic motivation with that of existing methods (i.e., beep sound, vibration, peppermint scent, and chewing gum) in maintaining arousal level through the experiment performing a monitoring task, simulating autonomous driving. From the results of subjective assessment, physiological indices, and performance, the proposed method achieved the same effects as vibration or chewing gum and resulted in reduced discomfort compared with beep sound and vibration.
