Human cortical areas activated in relation to vergence eye movements - A PET study

Human cortical areas activated in relation to vergence eye movements were d etermined using positron emission tomography. Binocular disparity-driven vi sual stimuli were presented using a head-mounted display. Eye movements wer e monitored continuously by an infrared limbus tracker. A combination of a bar and a cross was used as the target. In the vergence task, subjects were instructed to follow an approaching bar, while ignoring a stationary cross . Activation in relation to vergence eye movement was discriminated from ac tivation in relation to motion vision by using the ignore-bar task, as the control. In the ignore-bar task, subjects were instructed to fixate on a st ationary cross, while ignoring an approaching bar. The fixation task was us ed as the basic control for both the vergence and the ignore-bar tasks. Are as of activation in relation to vergence eye movements were found in the bi lateral temporooccipital junction, the left inferior parietal lobule, and t he right fusiform gyrus by comparing regional cerebral how between the verg ence and ignore-bar tasks and by the conjunctive analyses of vergence-vs-ig nore comparison with vergence-vs-fixation comparison. (C) 1999 Academic Pre ss.