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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 6 of 18) Page 6 of 18

The potential value of virtual performance feedback for NP rehabilitation applications can also be conjectured from applications designed to support physical therapy in adults following a stroke (Jack et al., 2001; Deutsch, Latonio, Burdea, & Boian, 2001). These applications use various glove and ankle VR interface devices that translate the user's movements into a visible and somewhat relevant activity that is presented graphically on a flatscreen display. For example, in one application, as the user performs a prescribed hand exercise designed to enhance fractionation (independence of finger motion), the image of a hand appears on the display, playing a piano keyboard, reflecting the actual hand movements of the client. In a similar application, the appropriate hand movement moves a "wiper" that serves to reveal an interesting picture along with display of a graphic rendering of a performance meter representing range of movement. These features not only serve as a mechanism for providing feedback regarding the ongoing status of targeted movement, but could be potentially used as a motivator. Results from this lab with stroke patients, presented in a series of seven case studies, reported positive results for rehabilitating hand performance across range, speed, fractionation and strength measures (Jack et al., 2001). In one noteworthy case, functional improvement was reported in a patient who was able to button his shirt independently for the first time post-stroke following two weeks of training with the VR hand interface. As well, by making the repetitive and sometimes boring work of physical therapy exercise more interesting and compelling, patients reported enhanced enjoyment leading to increased motivation.

For assessment purposes, although performance feedback is not typically a component of traditional testing, there may be a well-matched place for it in the emerging area of "dynamic" testing (Sternberg, 1997). In a critique of traditional cognitive and ability performance testing, Sternberg posits that dynamic interactive testing provides a new option that could supplement traditional "static" tests. The dynamic assessment approach requires the provision of guided performance feedback as a component in tests that measure learning. This method appears well suited to the assets available with VR technology. In fact, VEs might be the most efficient vehicle for conducting dynamic testing in an ecologically valid manner while still maintaining an acceptable level of experimental control.

4. The provision of "cueing" stimuli or visualization tactics designed to help guide successful performance to support an error-free learning approach.

The capacity for dynamic stimulus delivery and control within a VE also allows for the presentation of cueing stimuli that could be used for "error-free" learning approaches in cognitive rehabilitation scenarios. This asset underscores the idea that in some cases it may not be desirable for VR to simply mimic reality with all its incumbent limitations. Instead, stimulus features that are not easily deliverable in the real-world can be presented in a VE to help guide and train successful performance. In this special case of stimulus delivery, cues are given to the patient prior to a response in order to help guide successful error-free performance. Error-free training in contrast to trial and error learning has been shown to be successful in a number of investigations with such diverse subjects as pigeons to persons with developmental disabilities, schizophrenia, as well as a variety of CNS disorders (see Wilson and Evans, 1996 for review).

The basis for these findings regarding error-free learning may lie in reports that indicate that in persons with neurologically based memory impairment, certain memory/learning processes often remain relatively intact. Procedural, or skill memory, is one such cognitive operation (Cohen & Squire, 1980; Charness, Milberg, & Alexander, 1988). This type of memory ability concerns the capacity to learn rule-based or automatic procedures including motor tasks, certain kinds of rule based puzzles, and sequences for running or operating equipment, tools, computers, etc. (Sohlberg & Mateer, 1989;). Procedural memory can be viewed in contrast to declarative, or fact-based memory, which is usually more impaired following CNS insult and less amenable to rehabilitative improvement. Additionally, patients often demonstrate an ability to perform procedural tasks without any recollection of the actual training. This is commonly referred to as implicit memory (Graf & Schacter, 1985) and its presence is indicative of a preserved ability to process and retain new material without the person's conscious awareness of when or where the learning occurred.

Virtual Reality, by way of its interactive and immersive features, could provide training environments that foster cognitive/functional improvement by exploiting a person's preserved procedural abilities. Hence, cognitive processes could be restored via procedures practiced successfully and repetitively within a VE that contains functional real-world demands. Whether the person actually had any declarative recall of the actual training episodes is irrelevant, as long as the learned process or skill is shown to generalize to functional situations. Error-free learning strategies could be well integrated into a VE by way of thoughtful presentation of cueing stimuli within dynamic stimulus presentations. The real challenge would then be to somehow translate difficult declarative (and semantic) tasks into procedural learning activities, with the goal being the restoration of the more complex higher reasoning abilities.

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

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