Hemisphere-dependent XXXX in @entity1805 : Sightblindness in the 'intact' visual field.

@entity1 @entity650 @entity227 @entity75 @entity21244 @entity51 @entity1805 @entity2300
OBJECTIVES: In addition to exhibiting a severe contralesional deficit, @entity2300 @entity1 may also show a @entity227 , called sightblindness (the reverse case of 'blindsight). We have tested for the presence, nature and extent of such an @entity227 in @entity2300 @entity1 that we assigned to perform two visual tasks. Namely, we aimed to ascertain any links between this @entity51 , the lesion side, and the tasks performed or the stimuli used. METHODS: We tested left and right homonymous @entity2300 (right brain-damaged RBD and left brain-damaged @entity21244 , respectively) @entity1 and healthy controls. Natural-scene images, either non-filtered or filtered in low or high spatial frequency (LSF or @entity650 , respectively) were presented in the @entity227 of each subject. For the two tasks, detection ("Is an image present?") and categorization ("Is the image of a forest or a city?"), accuracy and response time were recorded. RESULTS: In the @entity227 the RBD (left hemianopes) @entity1 made more errors on the categorization task than did their matched controls, regardless of image type. In contrast, the only task in which the @entity21244 ( @entity2300 ) @entity1 made more errors than did the controls was the @entity650 -images task. Furthermore, in both tasks (detection and categorization), the RBD @entity1 performed worse than did the @entity21244 @entity1 . DISCUSSION: @entity1805 @entity1 do indeed exhibit a specific @entity227 in their @entity227 , which was previously thought to be unaffected. We have demonstrated that the nature and severity of this @entity51 is determined by the side of the @entity75 as well as by the tasks and the stimuli. Our findings corroborate the idea of hemispheric specialization at the occipital level, which might determine the nature and severity of @entity51 in @entity2300 @entity1 .
