Blindsight in subjects with homonymous visual field defects. Export

@article{citeulike:1724107, abstract = {Brain damage in the visual system can lead to apparently blind visual areas. However, more elaborate testing indicates that some visual ability may still exist for specific stimuli in the otherwise blind regions. This phenomenon is called 'blindsight' if subjects report no conscious awareness of visual stimuli but when forced to guess, nevertheless perform better than chance. It has mainly been suggested that secondary visual pathways are responsible for this phenomenon. However, no published study has clearly shown the neural mechanism responsible for blindsight. Furthermore, experimental artifacts may have been responsible for the appearance of the phenomenon in some subjects. In the present study, the visual fields of nine subjects were mapped and residual visual performance was examined in many areas using three different experimental procedures. Artifacts such as stray light or eye movements were well controlled. In addition, confidence ratings were required after each trial in the forced-choice tests. The results show that only one subject with a lesion in the optic radiation had blindsight in two discrete areas of the affected visual field. Spared optic radiation fibers of the main (primary) geniculo-striate visual pathway were most likely to account for this finding.}, address = {Department of Psychology, University of Western Australia, Nedlands 6907, Australia.}, author = {Scharli, H. and Harman, A. M. and Hogben, J. H.}, citeulike-article-id = {1724107}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/9950714}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=9950714}, issn = {0898-929X}, journal = {J Cogn Neurosci}, keywords = {blindsight}, month = {January}, number = {1}, pages = {52--66}, posted-at = {2007-10-03 14:58:12}, priority = {2}, title = {Blindsight in subjects with homonymous visual field defects.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/9950714}, volume = {11}, year = {1999} }

TY - JOUR ID - citeulike:1724107 L3 - citeulike-article-id:1724107 N2 - Brain damage in the visual system can lead to apparently blind visual areas. However, more elaborate testing indicates that some visual ability may still exist for specific stimuli in the otherwise blind regions. This phenomenon is called 'blindsight' if subjects report no conscious awareness of visual stimuli but when forced to guess, nevertheless perform better than chance. It has mainly been suggested that secondary visual pathways are responsible for this phenomenon. However, no published study has clearly shown the neural mechanism responsible for blindsight. Furthermore, experimental artifacts may have been responsible for the appearance of the phenomenon in some subjects. In the present study, the visual fields of nine subjects were mapped and residual visual performance was examined in many areas using three different experimental procedures. Artifacts such as stray light or eye movements were well controlled. In addition, confidence ratings were required after each trial in the forced-choice tests. The results show that only one subject with a lesion in the optic radiation had blindsight in two discrete areas of the affected visual field. Spared optic radiation fibers of the main (primary) geniculo-striate visual pathway were most likely to account for this finding. IS - 1 JF - J Cogn Neurosci SN - 0898-929X AD - Department of Psychology, University of Western Australia, Nedlands 6907, Australia. EP - 66 TI - Blindsight in subjects with homonymous visual field defects. VL - 11 SP - 52 KW - blindsight AU - Scharli, H AU - Harman, AM AU - Hogben, JH PY - 1999/01// UR - http://view.ncbi.nlm.nih.gov/pubmed/9950714 ER -