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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 4 of 18) Page 4 of 18

This point is also illustrated in a number of examples where VR has been applied to target executive functioning and wayfinding. In the mid-90's, using graphic imagery that would be considered primitive by today's standards, Pugnetti et al. (1995; 1998) developed a head mounted display delivered VR scenario that embodied the cognitive challenges that characterize the Wisconsin Card Sorting Test (WCST). The scenario consisted of a virtual building within which users were required to use environmental clues to aid in the correct selection of appropriate doorways needed to pass from room to room through the structure. The doorway choices varied according to the categories of shape, color and number of portholes. Similar to the WCST, the correct choice criteria were changed after a fixed number of successful trials, and the user was then required to shift cognitive set, look for clues and devise a new choice strategy in order to successfully pass into the next room. In one study, Pugnetti et al. (1998) compared a mixed group of neurological patients (multiple sclerosis, stroke, and traumatic brain injury) with normals' performance on both the WCST and on this head mounted display executive function system. Results indicated that the VR results mirrored previous anecdotal observations by family members of everyday performance deficits in the patient populations. Though the psychometric properties of the VE task were comparable to the WCST in terms of gross differentiation of patients and controls, weak correlations between the two methods suggested that the methods measured different aspects of these functions. A detailed analysis of the VR task data indicated that specific preservative errors appeared earlier in the test sequence compared to the WCST. The authors suggested that "…this finding depends on the more complex (and complete) cognitive demands of the VE setting at the beginning of the test when perceptuomotor, visuospatial (orientation), memory, and conceptual aspects of the task need to be fully integrated into an efficient routine" (p.160). The detection of these early "integrative" difficulties for this complex cognitive function may be particularly relevant for the task of predicting real world capabilities from test results.

This was further evidenced in a detailed single subject case study of a stroke patient using this system. In this report (Mendozzi, Motta, Barbieri, Alpini & Pugnetti, 1998), results indicated that the VR system was more accurate in identifying executive function deficits in a highly educated patient two years post-stroke, who had a normal WCST performance. The VR system, although using graphic imagery that would never be mistaken for the real world, was successful in detecting deficits that had been reported to be limiting the patient's everyday performance, yet were missed using existing NP tests. These results are in line with the observation that patients with executive disorders often perform relatively well on traditional NP tests of 'frontal lobe function', yet show marked impairment in controlling and monitoring behavior in real-life situations (Shallice & Burgess, 1991).

Similar findings were recently reported by McGeorge et al. (2001) in a study comparing real world and virtual world "errand running" performance in five traumatic brain injury patients and five matched normal controls. The selection of the patient sample for this study was based on staff ratings that indicated poor planning skills. However, the patient and control groups did not differ significantly from normative values on the Behavioural Assessment of the Dysexecutive Syndrome (BADS) battery (Wilson, Alderman, Burgess, Emslie & Evans, 1996). Video taped performance of subjects was coded and compared while performing a series of errands in the University of Aberdeen psychology department (real world) and within a flatscreen VR scenario modeled after this environment. Performance in both the real and virtual environment, as defined as the number of errands completed in a 20-minute period, was highly correlated (r = .79; p<.01). Interestingly, while the groups did not differ on age-corrected standardized scores on the BADS, significant differences were found between the groups in both the real world and virtual testing. This finding suggests several things. First, performance in the real and virtual world was functionally similar, second, patient and control groups could be discriminated equally using real and virtual tests while this discrimination was not picked up by standardized testing with the BADS, and third, that both measures of real and virtual world performance showed concordance with staff observations of planning skills. That these results support the view that VR testing may possess higher ecological value is in line with the observation by Shallice and Burgess (1991) that traditional NP tests do not demand the planning of behavior over more than a few minutes, or the prioritization of competing subtasks and may result in less effective prediction of real world performance.

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

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