The Low/High Index of Pupillary Activity (LHIPA), an eye-tracked measure of pupil diameter oscillation, is redesigned and implemented to function in real-time. The novel Real-time IPA (RIPA) is shown to discriminate cognitive load in re-streamed data from earlier experiments. Rationale for the RIPA is tied to the functioning of the human autonomic nervous system yielding a hybrid measure based on the ratio of Low/High frequencies of pupil oscillation. The paper's contribution is drawn from provision of documentation of the calculation of the RIPA. As with the LHIPA, it is possible for researchers to apply this metric to their own experiments where a measure of cognitive load is of interest.

Vibrotactile feedback is widely used in mobile devices because it provides a discreet and private feedback channel. Gaze-based interaction, on the other hand, is useful in various applications due to its unique capability to convey the focus of interest. Gaze input is naturally available as people typically look at things they operate, but feedback from eye movements is primarily visual. Gaze interaction and the use of vibrotactile feedback have been two parallel fields of human–computer interaction research with a limited connection. Our aim was to build this connection by studying the temporal and spatial mechanisms of supporting gaze input with vibrotactile feedback. The results of a series of experiments showed that the temporal distance between a gaze event and vibrotactile feedback should be less than 250 ms to ensure that the input and output are perceived as connected. The effectiveness of vibrotactile feedback was largely independent of the spatial body location of vibrotactile actuators. In comparison to other modalities, vibrotactile feedback performed equally to auditory and visual feedback. Vibrotactile feedback can be especially beneficial when other modalities are unavailable or difficult to perceive. Based on the findings, we present design guidelines for supporting gaze interaction with vibrotactile feedback.

Abstract Kinaesthetic interaction using force-feedback devices is promising in virtual reality. However, the devices are currently not suitable for interactions within large virtual spaces because of their limited workspace. We developed a novel gaze-based kinaesthetic interface that employs the user’s gaze to relocate the device workspace. The workspace switches to a new location when the user pulls the mechanical arm of the device to its reset position and gazes at the new target. This design enables the robust relocating of device workspace, thus achieving an infinite interaction space, and simultaneously maintains a flexible hand-based kinaesthetic exploration. We compared the new interface with the scaling-based traditional interface in an experiment involving softness and smoothness discrimination. Our results showed that the gaze-based interface performs better than the traditional interface, in terms of efficiency and kinaesthetic perception. It improves the user experience for kinaesthetic interaction in virtual reality without increasing eye strain.

An emerging use of mobile video telephony is to enable joint activities and collaboration on physical tasks. We conducted a controlled user study to understand if seeing the gaze of a remote instructor is beneficial for mobile video collaboration and if it is valuable that the instructor is aware of sharing of the gaze. We compared three gaze sharing configurations, (a) Gaze_Visible where the instructor is aware and can view own gaze point that is being shared, (b) Gaze_Invisible where the instructor is aware of the shared gaze but cannot view her own gaze point and (c) Gaze_Unaware where the instructor is unaware about the gaze sharing, with a baseline of shared-mouse pointer. Our results suggests that naturally occurring gaze may not be as useful as explicitly produced eye movements. Further, instructors prefer using mouse rather than gaze for remote gesturing, while the workers also find value in transferring the gaze information.

Remote collaboration on physical tasks is an emerging use of video telephony. Recent work suggests that conveying gaze information measured using an eye tracker between collaboration partners could be beneficial in this context. However, studies that compare gaze to other pointing mechanisms, such as a mouse-controlled pointer, in video-based collaboration, have not been available. We conducted a controlled user study to compare the two remote gesturing mechanisms (mouse, gaze) to video only (none) in a situation where a remote expert saw video of the desktop of a worker where his/her mouse or gaze pointer was projected. We also investigated the effect of distraction of the remote expert on the collaborative process and whether the effect depends on the pointing device. Our result suggests that mouse and gaze pointers lead to faster task performance and improved perception of the collaboration, in comparison to having no pointer at all. The mouse outperformed the gaze when the task required conveying procedural instructions. In addition, using gaze for remote gesturing required increased verbal effort for communicating both referential and procedural messages.

Video communication using head-mounted cameras could be useful to mediate shared activities and support collaboration. Growing popularity of wearable gaze trackers presents an opportunity to add gaze information on the egocentric video. We hypothesized three potential benefits of gaze-augmented egocentric video to support collaborative scenarios: support deictic referencing, enable grounding in communication, and enable better awareness of the collaborator's intentions. Previous research on using egocentric videos for real-world collaborative tasks has failed to show clear benefits of gaze point visualization. We designed a study, deconstructing a collaborative car navigation scenario, to specifically target the value of gaze-augmented video for intention prediction. Our results show that viewers of gaze-augmented video could predict the direction taken by a driver at a four-way intersection more accurately and more confidently than a viewer of the same video without the superimposed gaze point. Our study demonstrates that gaze augmentation can be useful and encourages further study in real-world collaborative scenarios.

In a study with 12 participants we compared two smooth pursuit based widgets and one dwell time based widget in adjusting a continuous value. The circular smooth pursuit widget was found to be about equally efficient as the dwell based widget in our color matching task. The scroll bar shaped smooth pursuit widget exhibited lower performance and lower user ratings.

Communicating spatial information by pointing is ubiquitous in human interactions. With the growing use of head-mounted cameras for collaborative purposes, it is important to assess how accurately viewers of the resulting egocentric videos can interpret pointing acts. We conducted an experiment to compare the accuracy of interpreting four different pointing techniques: hand pointing, head pointing, gaze pointing and hand+gaze pointing. Our results suggest that superimposing the gaze information on the egocentric video can enable viewers to determine pointing targets more accurately and more confidently. Hand pointing performed best when the pointing target was straight ahead and head pointing was the least preferred in terms of ease of interpretation. Our results can inform the design of collaborative applications that make use of the egocentric view.

The best way to construct user interfaces for smart glasses is not yet known. We investigated the use of eye tracking in this context in two experiments. The eye and head movements were combined so that one can select the object to interact by looking at it and then change a setting in that object by turning the head horizontally. We compared three different techniques for mapping the head turn to scrolling a list of numbers with and without haptic feedback. We found that the haptic feedback had no noticeable effect in objective metrics, but it sometimes improved user experience. Direct mapping of head orientation to list position is fast and easy to understand, but the signal-to-noise ratio of eye and head position measurement limits the possible range. The technique with constant rate of change after crossing the head angle threshold was simple and functional, but slow when the rate of change is adjusted to suit beginners. Finally the rate of change dependent on the head angle tends to lead to fairly long task completion times, although in theory it offers a good combination of speed and accuracy.

Anticipating the emergence of gaze tracking capable mobile devices, we are investigating the use of gaze as an input modality in handheld mobile devices. We conducted a study of combining gaze gestures with vibrotactile feedback. Gaze gestures were used as an input method in a mobile device and vibrotactile feedback as a new alternative way to give confirmation of interaction events. Our results show that vibrotactile feedback significantly improved the use of gaze gestures. The tasks were completed faster and rated easier and more comfortable when vibrotactile feedback was provided.

Consistent measuring and reporting of gaze data quality is important in research that involves eye trackers. We have developed TraQuMe: a generic system to evaluate the gaze data quality. The quality measurement is fast and the interpretation of the results is aided by graphical output. Numeric data is saved for reporting of aggregate metrics for the whole experiment. We tested TraQuMe in the context of a novel hidden calibration procedure that we developed to aid in experiments where participants should not know that their gaze is being tracked. The quality of tracking data after the hidden calibration procedure was very close to that obtained with the Tobii's T60 trackers built-in 2 point, 5 point and 9 point calibrations.