A new method to measure higher visual functions in an immersive environment.
Background: Higher visual functions can be defined as cognitive processes responsible for object recognition, color and shape perception, and motion detection. People with impaired higher visual functions after unilateral brain lesion are often tested with paper pencil tests, but such tests do not a...
| Publicado en: | BioMedical Engineering OnLine Vol. 13; pp. 104 - 105 |
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| Autores principales: | , , , , |
| Formato: | research Journal Article |
| Publicado: |
BioMed Central
2014
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=107798644&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 107798644 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 1475925X 1CGX jtl: BioMedical Engineering OnLine issn: 1475925X maglogo: N pubinfo: dt: 2014 vid: 13 pid: 24147 pub: BioMed Central artinfo: ui: 107798644 107798644 NLM25069675 2012676415 10.1186/1475-925X-13-104 NLM25069675 PMC4118661 107798644 ppf: 104 ppct: 1 formats: tig: atl: A new method to measure higher visual functions in an immersive environment. aug: au: Zito, Giuseppe A Müri, René Mosimann, Urs P Nyffeler, Thomas Nef, Tobias affil: Gerontechnology and Rehabilitation Group, University of Bern, Bern, Switzerland. tobias.nef@artorg.unibe.ch. sug: subj: Environment Vision Tests Methods Visual Perception Adult Aged Female Human Male Middle Age Pilot Studies Questionnaires Vision Tests Equipment and Supplies Young Adult Adult: 19-44 years Aged: 65+ years Middle Aged: 45-64 years Female Male ab: Background: Higher visual functions can be defined as cognitive processes responsible for object recognition, color and shape perception, and motion detection. People with impaired higher visual functions after unilateral brain lesion are often tested with paper pencil tests, but such tests do not assess the degree of interaction between the healthy brain hemisphere and the impaired one. Hence, visual functions are not tested separately in the contralesional and ipsilesional visual hemifields.Methods: A new measurement setup, that involves real-time comparisons of shape and size of objects, orientation of lines, speed and direction of moving patterns, in the right or left visual hemifield, has been developed. The setup was implemented in an immersive environment like a hemisphere to take into account the effects of peripheral and central vision, and eventual visual field losses. Due to the non-flat screen of the hemisphere, a distortion algorithm was needed to adapt the projected images to the surface. Several approaches were studied and, based on a comparison between projected images and original ones, the best one was used for the implementation of the test. Fifty-seven healthy volunteers were then tested in a pilot study. A Satisfaction Questionnaire was used to assess the usability of the new measurement setup.Results: The results of the distortion algorithm showed a structural similarity between the warped images and the original ones higher than 97%. The results of the pilot study showed an accuracy in comparing images in the two visual hemifields of 0.18 visual degrees and 0.19 visual degrees for size and shape discrimination, respectively, 2.56° for line orientation, 0.33 visual degrees/s for speed perception and 7.41° for recognition of motion direction. The outcome of the Satisfaction Questionnaire showed a high acceptance of the battery by the participants.Conclusions: A new method to measure higher visual functions in an immersive environment was presented. The study focused on the usability of the developed battery rather than the performance at the visual tasks. A battery of five subtasks to study the perception of size, shape, orientation, speed and motion direction was developed. The test setup is now ready to be tested in neurological patients. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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