Attentional mechanisms important in visual behavior were studied in patients with a variety of central nervous system abnormalities. Shifts of visual attention as measured by reaction times were measured in patients with parietal lobe damage, and compared to patients with frontal lobe damage, Alzheimer's disease, or schizophrenia. The patients with parietal lobe dysfunction demonstrated particular difficulty in shifting attention away from the ipsilateral visual field, and this finding was a reliable indicator of parietal cortical dysfunction. Male patients with idiopathic hypogonadotrophic hypogonadism also had abnormal responses: they were slow in responding to targets in their right visual field. Eye movements were evaluated in these patient groups, with pursuit movements and fixational stability emphasized. In some patients, square wave jerks present during fixation and reading were indications of attentional disorders.
