We studied three subjecta who reported the apparent “disapearance” of stationary objecte from direct view. They had simultanagnosia caused by CT-verified bilateral superior occipital lobe lesions. They had no abnormalities of visual acuity or fields to explain their defect. EOG with computer analysis showed intact motility and ecanning. Most important, the subjecta reported intermittent disappearance of a light target during Em-verified fixation—ie, they were looking but not seeing. Results indicate that attention mechanisms that permit sustained awareness of visual targets depend on the superior visual association cortices and are relatively separate from mechanisms that shift gaze and drive visual search.
ASJC Scopus subject areas
- Clinical Neurology