Analysis of Assets for Virtual Reality Applications in Neuropsychology Albert A. Rizzo, Maria Schultheis, Kimberly A. Kerns, and Catherine Mateer, Neuropsychological Rehabilitation (page 7 of 18) Page 7 of 18

Very few studies have examined the direct or specific effects of providing such cueing stimuli (compared to trial and error training) within a VE. In the only VR-based head-to-head comparison of this type, Connor et al. (2002), has reported a series of case studies on the use of a haptic joystick mediated "Trails B" type-training task. In the error-free condition, the haptic joystick restricted movement on a flatscreen Trails type task such that the patient was not allowed to make navigation errors. Mixed findings were reported, but error-free training resulted in significant response speed improvements compared to errorful training in some cases. Other studies have reported on the inclusion of an error-free component embedded within an overall VR training approach with more encouraging findings. For example, in the Brooks et al. (1999) case study previously cited, error-free training for wayfinding in a rehabilitation ward was one component in a VR training system that produced positive transfer to the real ward. Harrison et al. (2002) also reported the use of cueing stimuli in a VR system designed to train maneuverability and route-finding in novice motorized wheelchair users. This scenario provided a series of arrows that were presented with the caption "Go this way" to guide successful route navigation whenever the user would stray into areas where invisible "collision boxes" were programmed in the environment. Two patients with severe memory impairments took part in route finding training over the course of seven days. Post testing on the real routes produced mixed results with the patients successfully learning two subsections of the test routes but failing to eradicate errors on two further subsections of the routes. The investigators felt that further collision detection refinement of the system will be required to support accurate prompt delivery to patients before a more systematic group test will be possible.

Cueing stimuli have also been incorporated into a VE designed for executive function assessment and training in the context of a series of food preparation tasks within a virtual kitchen scenario (Christiansen et al., 1998). This scenario consists of a head mounted display VE of a kitchen in which patients have been assessed in terms of their ability to perform 30 discrete steps required to prepare a can of soup and make a sandwich. Various auditory and visual cues can be presented to help prompt successful performance. However the specific effect of this cueing has not been isolated, nor was a system in place to prevent errors from actually occurring (although successful usability findings--30 patients-minimal side effects--has been reported along with acceptable test/retest reliability coefficients for use of this system (Christiansen et al., 1998)). These researchers report ongoing enhancements to the system regarding the delivery of more complex challenges and increased flexibility in the presentation of cueing stimuli.

Generally, it appears that the provision of cueing stimuli to support error-free rehabilitation in a VE is promising in concept and supported by findings using traditional methods. However, empirical support in the form of systematic group VR data is still lacking. Part of the difficulty up to now has been due to programming challenges for tracking the user's position in the VE as was reported in Harrison et al. (2002), and for accurately providing prompts and restricting errors in an automatic fashion. This has become less of a problem with recent advances in collision detection and "physics" software, but still may be difficult as programming is typically not the clinician's primary skill. However, as better 'end-user' programming technologies come along, this may become less of an issue.

Technology challenges aside, VR-based research that could adequately explore the error-free "cueing" issue would require at least an errorless condition that could be compared with trial and error methods as seen in Connor et al. (2002). As well, the sensory mode of cue presentation should be explored to determine whether auditory cueing could be a useful option relative to the types of visual cues typically seen in the form of word captions and arrow pointers. If auditory cueing was found to be of equal effectiveness, it would reduce graphic requirements in system programming. Importantly, auditory prompting may also better resemble and "provoke" self-talk instruction methods that might support generalization to the real world of self-generated subvocal prompting on the part of the patient. If key prompting statements could be specified in advance, it would be possible to pre-record the patient speaking supportive cues in their own voice. When these cues are played back at strategic choice points within the VE, the patient could be directed more naturalistically by this form of "inner-voice" guidance. Also, since the early reports in this area have thus far mainly focused on spatial navigation and object localization, cues have been limited to the visual mode for pointing direction and labeling objects. Perhaps more complex tasks could be trained with inclusion of auditory cueing in this manner that could support error free training for the type of integrative problem solving required for effective executive functioning.

Finally, if the user-interfacing tools could be effectively designed, it would be possible to incorporate the use of various electronic compensatory devices into the VR interaction strategy as a method to deliver prompts in a fashion similar to how the patient is being encouraged to use these devices in the real world. This could take the form of assessing what level of "augmentive" information could actually be used by patients to assist in compensatory strategies aimed at improving day-to-day functional behavior and for training patient's effective use of these devices under a variety of environmental challenges.

From Neuropsychological Rehabilitation, 2004. 14(1/2), 207-239. Reprinted with permission from Albert Rizzo. All rights reserved.

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