Virtual environments as a tool for people with acquired brain injury

Författare

Mattias Wallergård

Summary, in English

People with acquired brain injury (ABI) often have problems leading an independent life due to impaired cognitive abilities. One way to address this is to let the patients practise activities of daily living as part of their rehabilitation process. However, some everyday activities can be difficult, inconvenient or risky to practise. The demands of the environment can also have an impact on the independence of an individual with ABI. Today, the involvement of people with ABI in the design of public space in minimal. Scarcely any regard is taken to this population when planning a new public transport system, for example. Accordingly, there is a need for development of methodology that can facilitate life for people with ABI. Virtual reality (VR) technology has shown great potential for various applications such as training, learning, visualisation and design. The objectives of the research presented in this doctoral thesis were to: 1) investigate how VR training can be used as a rehabilitation tool by people with ABI, and 2) explore if and how VR can be used to elicit knowledge about public transport accessibility for people with ABI.

The first research objective was investigated in four studies in which 60 able-bodied people with little or no experience of 3D computer graphics and 12 people with traumatic brain injury (TBI) participated. Case study methodology was applied, using observations, interviews and think-aloud protocols to collect data. One of the studies also used quantitative data and statistics. So called desktop VR (i.e. a standard monitor and regular input devices) was used. Three virtual environments were used: a kitchen, a cash dispenser and a hospital environment. In general, the results of the four studies suggest that VR has great potential as a training tool for people with ABI. However, the results also highlighted the importance of an optimised interface between the user and the VR system; seemingly small usability problems can create significant difficulties for a person with ABI. In the first study, a comparison was carried out between a joystick and a special keyboard for navigation in virtual training environments. There were two versions of each input device: one with two degrees of freedom and one with three. The keyboard was found to be more suitable for navigation tasks in which the user wants to give the viewpoint a more advantageous position and orientation for carrying out a specific task. No statistically significant differences between two and three degrees of freedom could be found. Nevertheless, the third degree of freedom, which made it possible to also move sideways, seemed to facilitate the navigation in some situations. The aim of the second study was to evaluate a method for interaction with virtual objects and to compare mouse and touch screen as input device for this purpose. The data showed no difference in performance between the mouse and touch screen subjects. Several touch screen subjects tended to imitate the way things are done in real life, however. This suggests that the touch screen is a more suitable input device in this context since the virtual activity resembles the real world activity. The third study investigated if and how five subjects with ABI could transfer route knowledge from a virtual hospital environment to the real world. They managed to walk a route they had only practised in a virtual environment, which suggests that VR-based route training can be a feasible complement to conventional route training. The aim of the fourth study was to develop and evaluate a virtual cash dispenser that can be used as a training tool by people with ABI. Seven people with ABI practised withdrawing money from the virtual cash dispenser. In general, they learned how to use the virtual cash dispenser. However, some usability problems, mainly related to interaction with virtual objects were noted. Another result, which could also be observed in the second study, was that unclear or non-existing feedback from the VR application was the cause of several of these problems.

The second research objective was addressed in two studies in which eleven people with ABI and four occupational therapists participated. Once again, case study methodology was used. Data was collected through observations, think-aloud protocols and interviews. Both studies used a virtual environment in which a complete bus trip could be performed. The first study evaluated a suggested VR methodology for enabling people with cognitive disabilities to communicate their knowledge and experiences of public transport systems. The users interacted with the VR system by verbally describing their actions to the person controlling the VR system and/or pointing with a laser pointer while seated in front of three screens on which the virtual environment was projected. Seven people with stroke were filmed as they made a virtual bus trip and were then asked to think aloud about their experience while watching the video material. Despite some initial difficulties, the subjects managed to communicate their intentions, some by combining verbalisations and pointing with the laser pointer in a very efficient manner. They were engaged in the virtual bus trip and made comments on the experience, including comments on emotional aspects. Interestingly, the subjects’ verbal descriptions of what they wanted to do revealed in part aspects of how they reasoned when taking the bus trip. The results suggested that the VR methodology can be a feasible tool for people with cognitive disabilities but also revealed several issues in need of improvement. The second study investigated if and how the VR methodology can be used to elicit knowledge from occupational therapists and people with ABI about public transport accessibility for the latter population. Four people with ABI made a virtual bus trip and afterwards were asked to think aloud about their experience while watching the video material from the bus trip. Four occupational therapists with experience of working with people with ABI performed the virtual bus trip while at the same time thinking aloud about public transport accessibility for people with ABI. Afterwards they watched the video material from the virtual bus trip of one of the subjects with ABI while once again thinking aloud about public transport accessibility. In general, both subject groups handled the VR methodology. The most relevant knowledge from the subjects with ABI was related to concrete accessibility problems, emotional aspects and strategies. The direct observations of the ABI subjects making the virtual bus trip led to the identification of some problems but revealed very little about what caused them. Instead, the cause of the problems came to light through the ABI subjects’ verbalisations, which demonstrates the importance of not only making observations but also paying attention to the participant’s subjective experience. The most relevant knowledge from the occupational therapists concerned the concrete accessibility problems and suggested solutions. Both think aloud sessions elicited unique knowledge from the occupational therapists and should therefore be part of the VR methodology in order to cover as many aspects as possible of public transport accessibility for people with ABI. Overall, the results suggested that the concept of first carrying out actions in a virtual environment and then reflecting over these actions seems to be a very good way of eliciting knowledge about public transport accessibility for people with ABI. The elicited knowledge from people with ABI and occupational therapists seems to illuminate, in part, different aspects of public transport accessibility and hence is complementary.

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