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Analysis of Assets for Virtual Reality Applications in Neuropsychology Albert A. Rizzo, Maria Schultheis, Kimberly A. Kerns, and Catherine Mateer, Neuropsychological Rehabilitation (page 5 of 18) Page 5 of 18

In the area of rehabilitation, a number of studies have supported the ecological value of VR training for wayfinding in both developmentally disabled teenagers navigating a supermarket (Cromby et al., 1996) and for school navigation in children in wheelchairs with limited experience in independent wayfinding (Stanton et al., 1998). Further initial support for the ecological value of VR wayfinding training, can be found in a case study by Brooks et al. (1999). In this report, a female stroke patient with severe amnesia showed significant improvements in her ability to find her way around a rehabilitation unit following training within a VE modeled after the unit. This was most notable given that prior to training, the patient had lived on the unit for two months and was still unable to find her way around, even to places she had visited regularly. In the first part of the training, improvements on two routes were seen after a three-week period of VE route practice lasting only 15 minutes per weekday and retention of this learning was maintained throughout the patient's stay on the unit. In the second part of the study, the patient was trained on two more routes, one utilizing the VE, and the other actually practicing on the "real" unit. Within two weeks the patient learned the route practiced in the VE, but not the route trained on the real unit, and this learning was maintained throughout the course of the study (Brooks et al., 1999). The authors account for this success as being due in part to the opportunity in the VE for quicker traversing of the environment than in the real world, which allowed for more efficient use of training time. Another factor in this success may be that the VE training did not contain the typical distractions normally present when real world training is conducted that might have impeded route learning. It might be found that the gradual fading in of distractions would be useful for inoculating the patient to the potentially deleterious impact of their inevitable presence in the real world and further enhance the ecological value of this form of rehabilitation.

These findings lend support to the view that due to the similarity of VR testing or training tasks with the demands of the real world, the enhancement in ecologically validity promotes the generalizability of such results to functional real world performance. Thus, VR assessment results could have enhanced clinical relevance and serve as a basis for the development of both restorative and contextual cognitive rehabilitation approaches. However, before this vision can be fully reached, technological advances need to occur in the area of human-computer interaction interfacing devices. Current technology is still limited in the degree to which a user can naturalistically interact with the challenges presented in a VE. From a human-computer interaction perspective, a primary concern involves how to design more naturalistic and intuitive tools for human interfacing with such complex systems. In order for persons with cognitive impairments to be in a position to benefit from VR applications, they must be able to learn how to navigate and interact within the environment. Many modes of VR interaction (i.e., data-gloves, joy sticks, 3D mice, etc.), while easily mastered by unimpaired users, could present problems for those with cognitive difficulties. Even if patients are capable of using a VR system at a basic level, the extra non-automatic cognitive effort required to interact/navigate could serve as a distraction and limit the assessment and rehabilitation processes. In this regard, Psotka (1995) hypothesizes that facilitation of a "single egocenter" found in highly immersive interfaces serves to reduce "cognitive overhead" and thereby enhance information access and learning. This is an area that needs the most attention in the current state of affairs for VR applications designed for populations with CNS dysfunction and an excellent review of these tools and issues can be found in Bowman, Kruijff, LaViola & Poupyrev (2001).

3. The delivery of immediate performance feedback in a variety of forms and sensory modalities.

The capacity for systematic delivery and control of stimuli presented to users in a VE can serve as a significant asset for the development of NP assessment and rehabilitation scenarios. This asset can also be harnessed to provide immediate performance feedback to users contingent on the status of their efforts. Such automated delivery of feedback stimuli can appear in graded (degree) or absolute (correct/incorrect) forms and can be presented via any or multiple sensory modalities (though mainly audio, visual, tactile is used) depending on the goals of the application and the needs of the user. This is an intuitively essential component for rehabilitation efforts as performance feedback is generally accepted to be necessary for most forms of learning or skill acquisition (Sohlberg & Mateer, 1989; 2001).

While VR-based feedback can be presented to signal performance status in a form that wouldn't naturally occur in the real world (e.g., a soft tone occurring after a correct response), more relevant or naturalistic sounds can also be creatively applied to enhance both ecological validity and the believability of the scenario. For example, in an Internet delivered VR application designed to help children with learning disabilities practice escape from a house fire (Strickland, 2001), the sound of a smoke detector alarm raises in volume as the child gets near to the fire's location. As the child successfully navigates to safety, the alarm fades contingent on her choosing the correct escape route. An efficacy study of this application is currently in progress (Dorothy Strickland, personal communication, Aug. 21, 2002).

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

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