New technologies have recently advanced user experiences in virtual reality (VR), whereas full sensation of diverse modalities has been not achieved yet. If any, haptic feedback has been delivered via bulky gloves. We have developed a novel thimble device that can deliver vibrotactile feedback via one fingertip. With this device, in the present study we investigated the effects of interaction methods and vibrotactile feedback on users' social presence, presence, engagement, workload, and performance in a cooperative VR game. Twenty-six participants wearing a VR headset played a cooperative VR game with the experimenter under four conditions: (1) controllers with no vibrotactile feedback, (2) controllers with vibrotactile feedback, (3) hand tracking with no vibrotactile feedback, and (4) hand tracking with vibrotactile feedback. Results showed that hand tracking improved participants' presence, engagement, and perceived workload compared to the traditional VR controllers. Also, vibrotactile feedback enhanced presence. However, the VR controllers outperformed the hand tracking interactions in completion time. The usability of hand interactions with vibrotactile feedback shows a promising result. We discuss the trade-offs between user experience and performance of the interaction methods and the potential of vibrotactile feedback in the VR environment.

Research has suggested that emotional states have critical effects on various cognitive processes, which are important components of situation awareness (Endsley, 1995b). Evidence from driving studies has also emphasized the importance of driver situation awareness for performance and safety. However, to date, little research has investigated the relationship between emotional effects and driver situation awareness. In our experiment, 30 undergraduates drove in a simulator after induction of either anger or neutral affect. Results showed that an induced angry state can degrade driver situation awareness as well as driving performance as compared to a neutral state. However, the angry state did not have an impact on participants' subjective judgment or perceived workload, which might imply that the effects of anger occurred below their level of conscious awareness. One of the reasons participants showed a lack of compensation for their deficits in performance might be that they were not aware of severe impacts of emotional effects on driving performance.