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Scientific Commentary |
The anatomy of blindsight
Institute of Cognitive Neuroscience & Wellcome Trust Centre for Neuroimaging, University College London, 17 Queen Square, London WC1N 3AR, UK
E-mail: g.rees@fil.ion.ucl.ac.uk
| The first 10% of the full text of this article appears below. |
Part of every neurological examination is an assessment of the visual field, obtained by asking patients to detect the presence of test targets on a defined background. Clinicians use either visual field testing to confrontation or more careful mapping and quantification of sensitivity of the visual field using automated perimetry. All of these approaches rely on the patient indicating whether they are aware of the presence of a test target at a particular location. Such testing can establish the presence of scotomas or blind regions of the visual field, where patients report that they do not perceive anything presented in such regions. Systematic correspondences between the location of visual field defects and the site of brain damage in the occipital lobe are sufficient to permit determination of a retinotopic map or projection of the retinal image onto