Studies of selective attention suggest a system which operates across modalities and on many forms of internal representation. Complex analysis, even semantic analysis, of sensory input may occur automatically, but attention controls the locus of action. When computations carried out by the brain are effortful, in the sense that elements compete…

Recently, knowledge of the mechanisms of visual-spatial attention has improved due to studies employing single cell recording with alert monkeys and studies using performance analysis of neurological patients. These studies suggest that a complex neural network including parts of the posterior parietal lobe and midbrain are involved in covert…

Work with patients with attentional deficits produced by posterior cerebral lesions has shown that such patients can identify words correctly even when they fail to report letters in nonwords contralateral to the lesion. Because of this, it has been assumed in cognitive neuropsychology that lesions do not produce new phenomena but instead provide…

Hypothesizes that the human brain localizes mental operations which are integrated in the performance of cognitive tasks such as reading. Provides support of this hypothesis from studies in neural imaging, mental imagery, timing, and memory. (RT)