Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> The time required to recognize that two perspective drawings portray objects of the same three-dimensional shape is found to be (i) a linearly increasing function of the angular difference in the portrayed orientations of the two objects and (ii) no shorter for differences corresponding simply to a rigid rotation of one of the two-dimensional drawings in its own picture plane than for differences corresponding to a rotation of the three-dimensional object in depth. <s> BIB001 </s> Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> We developed psychometric tests of spatial orientation ability, in which people are shown a two dimensional array of objects, imagine taking a perspective within the array, and indicate the direction to a target object from this perspective. Patterns of errors on these tests were consistent with experimental studies of perspective taking. Characteristic errors and verbal protocols supported the validity of the perspective-taking tests, suggesting that people encoded the objects in the display with respect to a body-centered coordinate system when the imagined perspective was more than 90° different from the orientation of the display. By comparing alternative models in a confirmatory factor analysis, we found that the ability to mentally rotate and manipulate an imagined object (as measured by tests of spatial visualization and spatial relations) and the ability to reorient the imagined self (as measured by the perspective-taking tests) are separable spatial abilities. <s> BIB002 </s> Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> Abstract Environmental spatial abilities are involved in everyday tasks such as finding one's way in the environment and learning the layout of a new environment. Self-report measures of environmental abilities, e.g., asking people to rate their “sense of direction (SOD),” have been found to predict objective measures of these abilities quite highly. In this study, we developed a standardized self-report scale of environmental spatial ability, the Santa Barbara Sense of Direction Scale (SBSOD). The scale proved to be internally consistent and had good test–retest reliability. A series of four validity studies examined its relation to measures of spatial updating and acquisition of spatial knowledge at different scales and acquired from different learning experiences. These studies suggested that the SBSOD is related to tasks that require one to update location in space as a result of self-motion. It is more highly correlated with tests of spatial knowledge that involve orienting oneself within the environment than with tests that involve estimating distances or drawing maps. Self-report SOD is also somewhat more highly correlated with measures of spatial knowledge acquired from direct experience in the environment than with measures of knowledge acquired from maps, video, or virtual environments (VE). <s> BIB003 </s> Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> Functional magnetic resonance imaging was performed in 16 healthy subjects while they undertook orientation discrimination tasks of real rotating and mentally rotating alphanumeric characters. Perception of rotating and stationary abstract characters was also performed. Mental rotation and the perception of alphanumeric characters undergoing real rotation activated equivalent cortical areas, in keeping with the analogue hypothesis of mental rotation. In addition, areas along the dorsal stream, including the V5/middle temporal complex and the intraparietal sulcus (IPS ), were activated during both the real and imaginary rotary conditions. Within the parietal lobe there were areas of convergence (i.e., recruited by all three motion conditions) and areas of divergence (i.e., selectively activated by a particular condition). Tasks requiring canonical-mirror orientation discrimination revealed involvement of neural substrates localized to the ventrolateral bank of the IPS. Tasks in which this judgment was not performed and during which the subject viewed rotary motion of abstract stimuli recruited activity in the medial bank of the IPS. These results indicate subspecialization of the human posterior parietal lobe according to function. <s> BIB004 </s> Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> Virtual reality (VR) possesses many qualities that give it rehabilitative potential for people with intellectual disabilities, both as an intervention and an assessment. It can provide a safe setting in which to practice skills that might carry too many risks in the real world. Unlike human tutors, computers are infinitely patient and consistent. Virtual worlds can be manipulated in ways the real world cannot be and can convey concepts without the use of language or other symbol systems. Published applications for this client group have all been as rehabilitative interventions. These are described in three groups: promoting skills for independent living, enhancing cognitive performance, and improving social skills. Five groups of studies are reviewed that utilize virtual technology to promote skills for independent living: grocery shopping, preparing food, orientation, road safety, and manufacturing skills. Fears that skills or habits learnt in a virtual setting would not transfer to the real world setting have not been supported by the available evidence, apart from those studies with people with autistic spectrum disorders. Future directions are in the development of more applications for independent living skills, exploring interventions for promoting motor and cognitive skills, and the developments of ecologically valid forms of assessment. <s> BIB005 </s> Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> Electronic games have been used to stimulate cognitive functions such as attention, concentration and memory. This paper presents GenVirtual, which is an augmented reality musical game and is proposed to help people with learning disabilities. The intention is to help the patient in the following skills: creativity, attention, memory (storage and retrieval), planning, concentration, ready-response, hearing and visual perception, and motor coordination. The therapist has flexibility to place the musical and visual elements, allowing him to create different scenarios to each patient. GenVirtual uses Augmented Reality technology to allow people with physical disorders to interact with the game. Patients with no fingers can also play this game. GenVirtual was evaluated by a music therapist who considered it as a facilitating and motivating game to the learning process and that it has the potential to improve the life of the people with special needs. <s> BIB006 </s> Application of Virtual Reality in Neuro-Rehabilitation: An Overview <s> VR-based systems for sensory, cognitive and behavioural rehabilitation <s> The rehabilitation of patients after a stroke must provide polisensoric cognitive therapy. A specially designed computer/information system suits well to these requirements and offers a complementary and holistic treatment, which can be used in a rehabilitation center and later at the patient's home. <s> BIB007
The traditional protocols for cognitive-behavioural rehabilitation are mostly based on imaginary or in-vivo exposure; the Virtual Reality Exposure Therapy (VRET) is an altered form of behavioral therapy and may be a possible alternative to standard in vivo exposure, for example in the therapy of anxiety disorders  . VR allows immersive or semiimmersive interaction with virtual environments incorporating suitable stimuli, therefore reducing the limits of representing real tools to brain damaged subjects unable to chategorize . VR systems are today in use in the management of patient with stroke, to support cognitive rehabilitation by providing logopaedic help and reducing the somatic effects of paresis though a multi-sensorial brain stimulation approach BIB007 ). Marusan and colleagues  and other groups   suggested the use of mental rotation paradigms BIB001 in VR neuro-rehabilitation setting, with extention to the brain injured of the use of mental images that is critical in cognitive tasks involving memory, reasoning and problem solving in everyday life  BIB004 . Marusan and coworkers main goal was to develop a VR-based technical solution for neurorehabilitation of traumatic brain injury (TBI) patients; their secondary goal was ease of use for the patient at home via common technical supports such as PC, mouse and keyboard devices to be available anywhere and anytime without special equipment (3D glasses, gloves, suits, etc) requiring expert help. Koenig and colleagues  ) proposed a VR approach to assess the patient's performance in tasks of way-finding and in the training of spatial orientation skills in brain injured patients. Several standardized outcome measures were used: Money Road-Map Test  , Zoo Test  , Object Perspective Taking Test BIB002 , Virtual Reality Navigation Task, Real-World Navigation Task, Santa Barbara Sense of Direction Scale BIB003 , Mental Rotation Task, Card Rotation Task, and Surface Development Task  . Complexity was increased with the protocol and subject's progressing in order to promote generalization of regained abilities, with the addition of naturalistic features or constraints (e.g. locked doors or detours) and varying conditions of illumination. Performance was evaluated as navigation errors, timing and orientation behaviour. Interactive multimodal rehabilitation may enhance the efficacy of cognitive rehabilitation after cerebrovascular brain injury. Salva and co-workers  ) have developed a novel Mixed Reality (MR) approach reportedly promoting neural plasticity. An evolution of classical VR merging and overlapping virtual and real environments, MR creates an augmented reality without losing contact with the real setting and preserving sensory feedback and interaction without any requirement for adaptation. The Mixed Reality Rehabilitation System (MRRS) was meant to avoid crucial problems in the traditional therapy such as the limitations in resources and decreasing levels of participation and interest. Pilot studies seem to indicate remarkable potentialities in neurorehabilitation though MR, mostly by allowing patients to interact with and experience both the virtual scenario and the real world BIB005 . Also based on Augmented Reality tools is GenVirtual BIB006 , a musical game helping patients in colors and sounds memorization tasks. The approach proved acceptable to the patient with cognitive deficits and useful in rehabilitation, inexpensive and applicable to integrate standard rehabilitation in hospital as well as at home.