Cueing spatial attention during processing of words and letter strings in normals

Abstract

Abstract Work with patients has shown that lesions of the right posterior cortex produce a deficit that affects ability to report letters on the left side of a foveal nonsense string but has little effect on foveal words. We have proposed that this is the result of a deficit in visual spatial attention. The current studies use cues on the left and right of foveally centred letter strings to bias visual spatial attention in normals. The studies show that the cues serve to bias report to the cued side very strongly for nonword letter strings and are less effective the more wordlike the string becomes. These results show that covert attention controls access of letters to consciousness in those cases where spatial attention is used to organise input.