Brain-computer interfaces (BCIs) can serve as a means for stroke rehabilitation, but low BCI performance can decrease agency (users' perceived control), frustrate users and thereby hamper rehabilitation. In such rehabilitative tasks BCIs can implement fabricated input (preprogrammed positive feedback) that improve agency and frustration. Two substudies with healthy subjects and stroke patients investigated this potential through completion of a game and a simple task with: 1) 16 healthy subjects using motor imagery-based online BCI and 2) 13 stroke patients using a surrogate BCI system based on eyeblink detection through an eye-tracker to have a highly reliable input signal. Substudy 1 measured perceived control and frustration in four conditions: 1) unaltered BCI control, 2) 30% guaranteed positive feedback from fabricated input 3) 50% guaranteed negative feedback, and 4) 50% guaranteed negative feedback and 30% guaranteed positive feedback. In substudy 2, stroke patients had 50% control over outcomes and four conditions added from 0% to 50% positive feedback. In both substudies, positive feedback improved participants' perceived control and reduced frustration with increasing improvements when the amount of positive fabricated input increased. The stroke patients did not react as much to the fabricated input as the healthy participants. Fabricated input can be concealed in both online and surrogate BCIs which can be used to improve perceived control and frustration in a game-based interaction and simple task. This suggests that BCI designers can exercise artistic freedom to create engaging motor imagery-based interactions of narrative-based games or simpler gamified interactions to facilitate improved training efforts.

Purpose: Virtual reality (VR) and eye tracking may provide detailed insights into spatial cognition. We hypothesized that virtual reality and eye tracking may be used to assess sub-types of spatial neglect in stroke patients not readily available from conventional assessments.Method: Eighteen stroke patients with spatial neglect and 16 age and gender matched healthy subjects wearing VR headsets were asked to look around freely in a symmetric 3D museum scene with three pictures. Asymmetry of performance was analyzed to reveal group-level differences and possible neglect sub-types on an individual level.Results: Four out of six VR and eye tracking measures revealed significant differences between patients and controls in this free-viewing task. Gaze-asymmetry between-pictures (including fixation time and count) and head orientation were most sensitive to spatial neglect behavior on a group level analysis. Gaze-asymmetry and head orientation each identified 10 out of 18 (56%), compared to 12 out of 18 (67%) for the best conventional test. Two neglect patients without deviant performance on conventional measures were captured by the VR and eyetracking measures. On the individual level, five stroke patients revealed deviant gaze-asymmetry within-pictures and six patients revealed deviant eye orientation in either direction that were not captured by the group-level analysis.Conclusion: This study is a first step in using VR in combination with eye tracking measures as individual differential neglect subtype diagnostics. This may pave the way for more sensitive and elaborate sub-type diagnostics of spatial neglect that may respond differently to various treatment approaches.

Motor imagery-based brain-computer interfaces (MI-BCI) have been proposed as a means for stroke rehabilitation, which combined with virtual reality allows for introducing game-based interactions into rehabilitation. However, the control of the MI-BCI may be difficult to obtain and users may face poor performance which frustrates them and potentially affects their motivation to use the technology. Decreases in motivation could be reduced by increasing the users' sense of agency over the system. The aim of this study was to understand whether embodiment (ownership) of a hand depicted in virtual reality can enhance the sense of agency to reduce frustration in an MI-BCI task. Twenty-two healthy participants participated in a within-subject study where their sense of agency was compared in two different embodiment experiences: 1) avatar hand (with body), or 2) abstract blocks. Both representations closed with a similar motion for spatial congruency and popped a balloon as a result. The hand/blocks were controlled through an online MI-BCI. Each condition consisted of 30 trials of MI-activation of the avatar hand/blocks. After each condition a questionnaire probed the participants' sense of agency, ownership, and frustration. Afterwards, a semi-structured interview was performed where the participants elaborated on their ratings. Both conditions supported similar levels of MI-BCI performance. A significant correlation between ownership and agency was observed (r = 0.47, p = 0.001). As intended, the avatar hand yielded much higher ownership than the blocks. When controlling for performance, ownership increased sense of agency. In conclusion, designers of BCI-based rehabilitation applications can draw on anthropomorphic avatars for the visual mapping of the trained limb to improve ownership. While not While not reducing frustration ownership can improve perceived agency given sufficient BCI performance. In future studies the findings should be validated in stroke patients since they may perceive agency and ownership differently than able-bodied users.

Self-management in health contexts requires patients to manage their own goal setting. Time series visualizations improve understanding of time-oriented data. But how they and interactions with them can support reflection and goal setting in selfmanagement is poorly understood. We compare findings from interviews with a health care professional and three stroke survivors on goal setting and reflection in a clinical setting with insights from a field study with one of the stroke survivors using a tablet application for self-care. Free text annotations of point plot score visualizations supported reflection but not long-term goal setting. The paper contributes a set of design guidelines for systems supporting people in their motivation and reflection in their self-rehabilitation.

An increasing number telehealth systems continuously collect selfreported data from patients. Objective and subjective collection of health data facilitates early detection and treatment of chronic conditions, but patient needs in these telehealth contexts are poorly understood. It is for example not clear how to support patients' reflection on their daily self-reported data. Inadequate support can result in fragmented daily health monitoring and poor adherence. This paper contributes 1) a synthesis of the related but hitherto disjunct personal informatics literature on self-tracking and 2) an indepth field study on how six people suffering chronic obstructive pulmonary disease (COPD) used a telehealth system as part of their health self-tracking. Our analysis showed that a telehealth solution which relegated patients to mere data suppliers missed out on opportunities to address user needs. We extended Li's 5-stage model to show where reflection manifested when interacting with the telehealth system.