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Positive Technology Journals

« 2007-07-11 | HomePage | 2007-07-14 »

Jul 13, 2007

A VR extended neuropsychological assessment for topographical disorientation

A virtual reality extended neuropsychological assessment for topographical disorientation: a feasibility study.

J Neuroengineering Rehabil. 2007 Jul 11;4(1):26

Authors: Morganti F, Gaggioli A, Strambi L, Rusconi ML, Riva G

ABSTRACT: BACKGROUND: Topographical disorientation represents one of the main consequences of brain injury. Up to now several methodological approaches have been used in the assessment of the brain injured patient's navigational abilities showing a moderate correlation with the impairments observed in everyday contexts. METHODS: We propose a combination of standardized neuropsychological tests and a more situated virtual reality-based assessment for the evaluation of spatial orientation in brain injured patients. RESULTS: When tested with this virtual reality integrated procedure patients showed performance and execution times congruent with their neuropsychological evaluation. When compared to a control group, patients revealed significantly slower times and greater errors in solving virtual reality based spatial tasks. CONCLUSIONS: The use of virtual reality, when combined with classical neuropsychological tests, can provide an effective tool for the study of topographical disorientation.

19:44 Posted in Research tools | Permalink | Comments (0) | Tags: virtual reality

Direct instrumental conditioning of neural activity using fMRI feedback

Direct instrumental conditioning of neural activity using functional magnetic resonance imaging-derived reward feedback.

J Neurosci. 2007 Jul 11;27(28):7498-507

Authors: Bray S, Shimojo S, O'Doherty JP

Successful learning is often contingent on feedback. In instrumental conditioning, an animal or human learns to perform specific responses to obtain reward. Instrumental conditioning is often used by behavioral psychologists to train an animal (or human) to produce a desired behavior. Shaping involves reinforcing those behaviors, which in a stepwise manner are successively closer to the desired behavior until the desired behavior is reached. Here, we aimed to extend this traditional approach to directly shape neural activity instead of overt behavior. To achieve this, we scanned 22 human subjects with functional magnetic resonance imaging and performed image processing in parallel with acquisition. We delineated regions of interest (ROIs) in finger and toe motor/somatosensory regions and used an instrumental shaping procedure to induce a regionally specific increase in activity by providing an explicit monetary reward to reinforce neural activity in the target areas. After training, we found a significant and regionally specific increase in activity in the ROI being rewarded (finger or toe) and a decrease in activity in the nonrewarded region. This demonstrates that instrumental conditioning procedures can be used to directly shape neural activity, even without the production of an overt behavioral response. This procedure offers an important alternative to traditional biofeedback-based approaches and may be useful in the development of future therapies for stroke and other brain disorders.

19:39 Posted in Biofeedback & neurofeedback | Permalink | Comments (0) | Tags: neurofeedback