Virtual reality ( VR ) displays have factors such as vergence-accommodation conflicts that negatively impact depth perception and cause users to misjudge distances to select objects. In addition, popular large-screen immersive displays present the depth of any target rendered through screen parallax information of points, which are encapsulated within stereoscopic voxels that are a distinct unit of space dictating how far an object is placed in front of or behind the screen. As they emanate from the viewers’ eyes (left and right center of projection), the density of voxels is higher in front of the screen (in regions of negative screen parallax) than it is behind the screen (in regions of positive screen parallax), implying a higher spatial resolution of depth in front of the screen than behind the screen. Our experiment implements a near-field fine-motor pick-and-place task in which users pick up a ring and place it around a targeted peg. The targets are arranged in a linear configuration of 3, 5, and 7 pegs along the front-and-back axis with the center peg placed in the same depth as the screen. We use this to evaluate how users manipulate objects in positive versus negative screen parallax space by the metrics of efficiency, accuracy, and economy of movement. In addition, we evaluate how users’ performance is moderated by haptic feedback and mismatch between visual and proprioceptive information. Our results reveal that users perform more efficiently in negative screen parallax space and that haptic feedback and visuo-proprioceptive mismatch have effects on placement efficiency. The implications of these findings are described in the later sections of the article.

The trade-off between speed and accuracy in precision tasks is important to evaluate during user interaction with input devices. When different sensory cues are added or altered in such interactions, those cues have an effect on this trade-off, and thus, they affect overall user performance. For instance, adding cues like haptic feedback and stereoscopic viewing will result in more realistic user interaction, thus improving performance in these tasks. Also, adding a noticeable disparity between physical and virtual movements creates a mismatch between visual and proprioceptive systems, which generally has a negative effect on performance. In this study, we investigate the effects of haptic feedback, stereoscopic viewing, and visuo-proprioceptive mismatch on how quickly and accurately users complete a virtual pick-and-place task using the PHANToM OMNI. Through this experiment, we find that in the movement phase of a ring transfer, movement time and user performance are affected by haptic feedback and visuo-proprioceptive mismatch, and the main effects of stereoscopic viewing appears to be limited to the more precise step when the ring is around the target peg.

We present an empirical evaluation on how stereoscopic viewing and haptic feedback deferentially affects fine motor perception-action coordination in a pick-and-place task in Virtual Reality (VR). The factors considered were stereoscopic viewing, haptic feedback, sensory-motor congruence and mismatch, and calibration on perception-action coordination in near field fine motor task performance in VR. Quantitative measures of placement error, distance, collision, and time to complete trials were recorded and analyzed. Overall, we found that participants' manual dexterous task performance was enhanced in the presence of both stereoscopic viewing and haptic feedback. However, we found that time to complete task was greatly enhanced by the presence of haptic feedback, and economy and efficiency of movement of the end effector as well as the manipulated object was enhanced by the presence of both haptic feedback and stereoscopic viewing. Whereas, number of collisions and placement accuracy were greatly enhanced by the presence of stereoscopic viewing in near-field fine motor perception-action coordination. Our research additionally shows that mismatch in sensory-motor stimuli can detrimentally affect the number of collisions, and efficiency of end effector and object movements in near-field fine motor activities, and can be further negatively affected by the absence of haptic feedback and stereoscopic viewing. In spite of reduced cue situations in VR, and the absence or presence of stereoscopic viewing and haptic feedback, we found that participants tend to calibrate or adapt their perception-action coordination rapidly with a set of at least 5 trials.

This paper details the results of an initial empirical evaluation conducted to examine how stereoscopic viewing and haptic feedback affects fine motor actions in a pick-and-place task, similar to the peg transfer task in an FLS training curriculum for laproscopic sugical training. In a between subjects experiment, we examined the effect of stereoscopic viewing and simulated tactile feedback during the fine motor actions of a participants' actions in the near field on the number of collisions and time to complete the task. We found that stereo and haptic feedback contributed to the effectiveness of task performance in different ways. Specifically, we found that the mean time to complete the trials was significantly higher in the abcense of tactile feedback as compared to when it was present, and the mean number of collisions was significantly higher in the presence of stereo as compared to when it was absent.

The need for virtual reality applications for education and training involving bimanual dexterous activities has been increasing in recent years. However, it is unclear how the amount of correspondence between a virtual interaction metaphor to the real-world equivalent, otherwise known as dimensional symmetry, affects bimanual pscyhomotor skills training and how skills learned in the virtual simulation transfer to the real world. How does the number of degrees of freedom enhance or hinder the learning process? Does the increase in dimensional symmetry affect cognitive load? In an empirical evaluation, we compare the effectiveness of a natural 6-DOF interaction metaphor to a simplified 3-DOF metaphor. Our simulation interactively educates users in the step-by-step process of taking a precise measurement using calipers and micrometers in a simulated technical workbench environment. We conducted a usability study to evaluate the user experience and pedagogical benefits using measures including a pre and post cognition questionnaire over all levels of Bloom's taxonomy, workload assessment, system usability, and real world psychomotor assessment tasks. Results from the pre and post cognition questionnaires suggest that learning outcomes improved throughout all levels of Bloom's taxonomy for both conditions, and trends in the data suggest that the 6-DOF metaphor was more effective in real-world skill transference compared to the 3-DOF metaphor.