Sense of agency at a gaze-contingent display with jittery temporal delay.

Introduction: Inconsistent jittery temporal delays between action and subsequent feedback, prevalent in network-based human-computer interaction (HCI), have been insufficiently explored, particularly regarding their impact on the sense of agency (SoA). This study investigates the SoA in the context of eye-gaze HCI under jittery delay conditions. Methods: Participants performed a visual search for Chinese characters using a biresolutional gaze-contingent display, which displayed a high-resolution image in the central vision and a low-resolution in the periphery. We manipulated the delay between eye movements and display updates using a truncated normal distribution (µ to µ + 2 σ) with µ ranging from 0 to 400 ms and σ fixed at 50 ms. Playback of recorded gaze data provided a non-controllable condition. Results: The study revealed that both reported authorship and controllability scores, as well as the fixation count per second, decreased as µ increased, aligning with trends observed under constant delay conditions. The subjective authorship weakened significantly at a µ of 94 ms. Notably, the comparison between jittery and constant delays indicated the minimum value (µ) of the distribution as a critical parameter influencing both authorship perception and visual search time efficiency. Discussion: This finding underscores the importance of the shortest delay in modulating SoA. Further examining the relative distribution for fixation duration and saccade amplitude suggests an adaptation in action planning and attention distribution in response to delay. By providing a systematic examination of the statistical attributes of jittery delays that most significantly affect SoA, this research offers valuable implications for the design of efficient, delay-tolerant eye-gaze HCI, expanding our understanding of SoA in technologically mediated interactions. Moreover, our findings highlight the significance of considering both constant and variable delay impacts in HCI usability design, marking a novel contribution to the field.

Toward a Hybrid Passive BCI for the Modulation of Sustained Attention Using EEG and fNIRS.

We report results of a study that utilizes a BCI to drive an interactive interface countermeasure that allows users to self-regulate sustained attention while performing an ecologically valid, long-duration business logistics task. An engagement index derived from EEG signals was used to drive the BCI while fNIRS measured hemodynamic activity for the duration of the task. Participants (n = 30) were split into three groups (1) no countermeasures (NOCM), (2) continuous countermeasures (CCM), and (3) event synchronized, level-dependent countermeasures (ECM). We hypothesized that the ability to self-regulate sustained attention through a neurofeedback mechanism would result in greater task engagement, decreased error rate and improved task performance. Data were analyzed by wavelet coherence analysis, statistical analysis, performance metrics and self-assessed cognitive workload via RAW-TLX. We found that when the BCI was used to deliver continuous interface countermeasures (CCM), task performance was moderately enhanced in terms of total 14,785 (σ = 423) and estimated missed sales 7.46% (σ = 1.76) when compared to the NOCM 14,529 (σ = 510), 9.79% (σ = 2.75), and the ECM 14,180 (σ = 875), 9.62% (σ = 4.91) groups. An "actions per minute" (APM) metric was used to determine interface interaction activity which showed that overall the CCM and ECM groups had a higher APM of 3.460 (SE = 0.140) and 3.317 (SE = 0.139) respectively when compared with the NOCM group 2.65 (SE = 0.097). Statistical analysis showed a significant difference between ECM - NOCM and CCM - NOCM (p < 0.001) groups, but no significant difference between the ECM - CCM groups. Analysis of the RAW-TLX scores showed that the CCM group had lowest total score 7.27 (σ = 3.1) when compared with the ECM 9.7 (σ = 3.3) and NOCM 9.2 (σ = 3.4) groups. No statistical difference was found between the RAW-TLX or the subscales, except for self-perceived performance (p < 0.028) comparing the CCM and ECM groups. The results suggest that providing a means to self-regulate sustained attention has the potential to keep operators engaged over long periods, and moderately increase on-task performance while decreasing on-task error.

How Is the Caregiver Doing? Capturing Caregivers' Experiences With a Reflective Toolkit.

BACKGROUND: This paper describes the Co-Care-KIT, a reflective toolkit designed to provide insights into the diverse experiences of home-based informal caregivers during the delivery of care to a relative or loved one. OBJECTIVE: The aim of this study was to evaluate the toolkit, including a custom-designed journal, tools for photography-based experience sampling, and heart rate tracking, which enables caregivers to collect and reflect on their positive and negative daily experiences in situ. METHODS: A 2-week field study with informal caregivers (N=7) was conducted to evaluate the Co-Care-KIT and to capture their daily personal emotional experiences. The collected data samples were analyzed and used for collaborative dialogue between the researcher and caregiver. RESULTS: The results suggest that the toolkit (1) increased caregivers' awareness of their own well-being through in situ reflection on their experiences; (2) empowered caregivers to share their identities and experiences as a caregiver within their social networks; (3) enabled the capturing of particularly positive experiences; and (4) provided caregivers reassurance with regards to their own mental health. CONCLUSION: By enabling capturing and collaborative reflection, the kit helped to gain a new understanding of caregivers' day-to-day needs and emotional experiences.