Oct 20, 2009

Inducing a virtual hand ownership illusion through a brain-computer interface

Inducing a virtual hand ownership illusion through a brain-computer interface.

Neuroreport. 2009 Apr 22;20(6):589-594

Authors: Perez-Marcos D, Slater M, Sanchez-Vives MV

The apparently stable brain representation of our bodies is easily challenged. We have recently shown that the illusion of ownership of a three-dimensional virtual hand can be evoked through synchronous tactile stimulation of a person's hidden real hand and that of the virtual hand. This reproduces the well-known rubber-hand illusion, but in virtual reality. Here we show that some aspects of the illusion can also occur through motor imagery used to control movements of a virtual hand. When movements of the virtual hand followed motor imagery, the illusion of ownership of the virtual hand was evoked and muscle activity measured through electromyogram correlated with movements of the virtual arm. Using virtual bodies has a great potential in the fields of physical and neural rehabilitation, making the understanding of ownership of a virtual body highly relevant.

Sep 21, 2009

Driving dreams: cortical activations during imagined passive and active whole body movemen

Driving dreams: cortical activations during imagined passive and active whole body movement.

Ann N Y Acad Sci. 2009 May;1164:372-5

Authors: Flanagin VL, Wutte M, Glasauer S, Jahn K

It is unclear how subjects perceive and process self-motion cues in virtual reality environments. Movement could be perceived as passive, akin to riding in a car, or active, such as walking down the street. These two very different types of self-motion were studied here using motor imagery in fMRI. In addition, the relative importance of visual and proprioceptive training cues was examined. Stronger activations were found during proprioceptive motor imagery compared with visual motor imagery, suggesting that proprioceptive signals are important for successful imagined movement. No significant activations were found during active movement with proprioceptive training. Passive locomotion, however, was correlated with activity in an occipital-parietal and parahippocampal cortical network, which are the same regions found during navigation with virtual reality stimuli.

Reactivity to cannabis cues in virtual reality environments

Reactivity to cannabis cues in virtual reality environments.

J Psychoactive Drugs. 2009 Jun;41(2):105-12

Authors: Bordnick PS, Copp HL, Traylor A, Graap KM, Carter BL, Walton A, Ferrer M

Virtual reality (VR) cue environments have been developed and successfully tested in nicotine, cocaine, and alcohol abusers. Aims in the current article include the development and testing of a novel VR cannabis cue reactivity assessment system. It was hypothesized that subjective craving levels and attention to cannabis cues would be higher in VR environments with cannabis cues compared to VR neutral environments. Twenty nontreatment-seeking current cannabis smokers participated in the VR cue trial. During the VR cue trial, participants were exposed to four virtual environments that contained audio, visual, olfactory, and vibrotactile sensory stimuli. Two VR environments contained cannabis cues that consisted of a party room in which people were smoking cannabis and a room containing cannabis paraphernalia without people. Two VR neutral rooms without cannabis cues consisted of a digital art gallery with nature videos. Subjective craving and attention to cues were significantly higher in the VR cannabis environments compared to the VR neutral environments. These findings indicate that VR cannabis cue reactivity may offer a new technology-based method to advance addiction research and treatment.

The sensitivity of a virtual reality task to planning and prospective memory impairments

The sensitivity of a virtual reality task to planning and prospective memory impairments: Group differences and the efficacy of periodic alerts on performance.

Neuropsychol Rehabil. 2009 Aug 26;:1-25

Authors: Sweeney S, Kersel D, Morris RG, Manly T, Evans JJ

Executive functions have been argued to be the most vulnerable to brain injury. In providing an analogue of everyday situations amenable to control and management virtual reality (VR) may offer better insights into planning deficits consequent upon brain injury. Here 17 participants with a non-progressive brain injury and reported executive difficulties in everyday life were asked to perform a VR task (working in a furniture storage unit) that emphasised planning, rule following and prospective memory tasks. When compared with an age and IQ-matched control group, the patients were significantly poorer in terms of their strategy, their time-based prospective memory, the overall time required and their propensity to break rules. An examination of sensitivity and specificity of the VR task to group membership (brain-injured or control) showed that, with specificity set at maximum, sensitivity was only modest (at just over 50%). A second component to the study investigated whether the patients' performance could be improved by periodic auditory alerts. Previous studies have demonstrated that such cues can improve performance on laboratory tests, executive tests and everyday prospective memory tasks. Here, no significant changes in performance were detected. Potential reasons for this finding are discussed, including symptom severity and differences in the tasks employed in previous studies.

Increased personal space of patients with schizophrenia in a virtual social environment

Increased personal space of patients with schizophrenia in a virtual social environment.

Psychiatry Res. 2009 Sep 15;

Authors: Park SH, Ku J, Kim JJ, Jang HJ, Kim SY, Kim SH, Kim CH, Lee H, Kim IY, Kim SI

Virtual reality may be a good alternative method for measuring personal space and overcoming some limitations in previous studies on the social aspects of schizophrenia. Using this technology, we aimed to investigate the characteristics of personal space in patients with schizophrenia and evaluate the relationship between their social behaviors and schizophrenic symptoms. The distance from a virtual person and the angle of head orientation while talking to a virtual person in a virtual environment were measured in 30 patients with schizophrenia and 30 normal controls. It was found that patients with schizophrenia had longer distances and larger angles than did normal controls. The severity of the negative syndrome had significant inverse correlations with the distance from the angry and neutral virtual persons and with the angle of head orientation toward the happy and angry virtual persons, suggesting that negative symptoms may have a close relationship with personal space, including distancing and eye gaze. The larger personal space of patients may reflect their discomfort in close situations or cognitive deficits. Showing these profiles to patients could help them realize the amount of personal space they need.

The use of biofeedback in clinical virtual reality: the intrepid project

The use of biofeedback in clinical virtual reality: the intrepid project.

Stud Health Technol Inform. 2009;144:128-32

Authors: Repetto C, Gorini A, Algeri D, Vigna C, Gaggioli A, Riva G

In our protocol for the treatment of Generalized Anxiety Disorders we use Virtual reality (VR) to facilitate emotional regulation and the relaxation process. Using a biofeedback biomonitoring system (GSR, HR, Thermal) the patient is made aware of his or her reactions through the modification of some features of the VR environment in real time. Using mental exercises the patient learns to control these physiological parameters and using the feedback provided by the virtual environment is able to gauge his or her success. To test this concept, we planned a randomized controlled trial (NCT00602212), including three groups of 15 patients each (for a total of 45 patients): (1) the VR group, (2) the non-VR group, and (3) the waiting list (WL) group.

Jun 15, 2009

Equivalence of Real-World and Virtual-Reality Route Learning

Equivalence of Real-World and Virtual-Reality Route Learning: A Pilot Study.

Cyberpsychol Behav. 2009 Jun 10;

Authors: Lloyd J, Persaud NV, Powell TE

Abstract There is good evidence for effective transfer of learning from virtual to real-world environments, and this holds true even for complex spatial tasks such as route learning. However, there is little research into the simple equivalence of an individual's performance across real and virtual environments, an important topic which could support the use of virtual reality as an assessment and research tool. This pilot study compared route-learning performance in a desktop virtual town with performance around a real-world route. Participants were "driven" around a route through a virtual town and around a different (but equally complex) route through a real-world suburb, then asked to direct the driver back around each of the routes from memory. They completed strategy checklists after learning each route. Results indicated good equivalence between the real and virtual environments, with comparable error rates and no differences in strategy preferences. This demonstrates that simple desktop virtual environments may be a useful tool for assessment of and research into route learning.

Apr 29, 2009

Ultimate virtual reality will trigger five senses

Via New Scientist

The New Scientist reports that researchers at University of York and the University of Warwick are designing a device able to manipulate five of a person's senses, to provide them with the illusion of being somewhere else.

Mar 05, 2009

Virtual Cocoon: The ultimate VR device for psychotherapy

Scientists from the Universities of York and Warwick have developed the first Virtual Reality system that allows users to see, hear, smell taste and even touch. The prototype will be presented at Pioneers 09', an EPSRC showcase event to be held at London's Olympia Conference Centre on March 4

If the prototype can really do what it promises, it can have widespread applications in education, business, medical visualization and cybertherapy.

Credit: Image courtesy of Engineering and Physical Sciences Research Council



 

Jan 20, 2009

Spatial aspects of bodily self-consciousness

Spatial aspects of bodily self-consciousness.

Conscious Cogn. 2008 Dec 22;

Authors: Lenggenhager B, Mouthon M, Blanke O

Visual, somatosensory, and perspectival cues normally provide congruent information about where the self is experienced. Separating those cues by virtual reality techniques, recent studies found that self-location was systematically biased to where a visual-tactile event was seen. Here we developed a novel, repeatable and implicit measure of self-location to compare and extend previous protocols. We investigated illusory self-location and associated phenomenological aspects in a lying body position that facilitates clinically observed abnormal self-location (as on out-of-body experiences). The results confirm that the self is located to where touch is seen. This leads to either predictable lowering or elevation of self-localization, and the latter was accompanied by sensations of floating, as during out-of-body experiences. Using a novel measurement we show that the unitary and localized character of the self can be experimentally separated from both the origin of the visual perspective and the location of the seen body, which is compatible with clinical data.

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