Walsh & Hoyt: Psychoanatomical Substrates in Balint's Syndrome

Twenty-four reports of ""simultanagnosia/Balints syndrome,"" compiled by the Oxford University Press, provide an overview of key theoretical issues, lesion localization, underlying pathology, and standardized assessment techniques employed. A diversity of deficits, lesions, vision assessment, and opinions is clearly evident in these articles. Rizzo and Vecera reviewed psychoanatomic substrates of Balints syndrome and emphasized the role of deficits of visual short-term memory (working memory) and attention. James defined attention in its modern sense as an ability that enhances our performance on behavioral tasks by focusing the mind on one item and withdrawing from other competing items. The report by Balint provided preliminary evidence of a neural substrate of attention. The lesions in his patient produced an attentional reduction in the visual fields manifested by failure to detect objects in the periphery (more so on the left). Indeed, reductions in the useful field of vision that are not caused by a visual field defect of luminance or form are now well described in elderly or demented patients. This effective field reduction is associated with difficulty functioning in a complex visual environment, such as encountered while driving a motor vehicle.