Location of the human frontal eye field as defined by electrical cortical stimulation: anatomical, functional and electrophysiological characteristics

Electrical cortical stimulation of the human frontal gyri and the precentra l gyrus has been shown to induce eye movements and it has classically been assumed that these stimulation-induced eye movements result from electrical interference with the human homologue of the monkey frontal eye field (FEF ). However, amplitude of electrical current and induced type of eye movemen t, which are essential for the determination of eye fields in the monkey, h ave not been investigated systematically in man. We applied electrical cort ical stimulation in the lateral frontal cortex in six epileptic patients. S ites whose stimulation resulted in eye movements were determined with respe ct to gyral and sulcal patterns, Talairach coordinates and neighboring func tions as found by electrical cortical stimulation. Based on this approach, a restricted location of the electrically defined FEF is proposed within a larger oculomotor region on the posterior part of the middle frontal gyrus. NeuroReport 11:1907-1913 (C) 2000 Lippincott Williams & Wilkins.