Visual activity in the human frontal eye field

ALTHOUGH visual information processing in the monkey frontal eye field (PEF ) has been well demonstrated, the contribution of its human homologue to vi sion is still unknown. Here we report a study of intracranial visual evoked potentials (VEPs) recorded from the human FEF which was identified by elec trical cortical stimulation. Electrical stimulations and EEG recordings wer e carried out via subdural grid electrodes placed over the frontal cortex i n three epileptic patients. Evoked eye movements were mainly horizontal and always directed to the hemispace contralateral to the stimulation site. In tracranial VEPs showed responses predominately to stimuli in the contralate ral visual field. Our findings demonstrate a close relationship between the direction of the electrically elicited eye movements and the visual stimul us location which predominantly leads to neural responses in the FEF. These findings provide evidence for the functional role of the human FEF in the analysis of visual stimuli from the contralateral visual field as well as i n the generation of eye movements towards these conspicuous targets. NeuroR eport 10:925-930 (C) 1999 Lippincott Williams & Wilkins.