After a study of optokinetic stimulation (OKN) with FLASH functional magnetic resonance imaging, which showed activation of a cerebral network of sensorimotor and subcortical areas (Bucher et al., 1997), we examined the three-dimensional representation of these activation patterns using fMRI multislice echo planar imaging. Five normal subjects, were examined on an 1.5 T scanner (Siemens Vision, Erlangen, Germany). Alternating periods of 5 images at rest followed 5 images during small-field OKN in a series of 50-100 T2*-weighted scans using an EPI sequence. Image analysis was performed on a UltraSPARC workstation (Sun Microsystems Inc.) using the SPM96 software package (The Welcome Department of Cognitive Neurology, Institute of Neurology, London, UK). The data were realigned, anatomically standardised in the stereotactic Talairach space, smoothed and analysed using a delayed box-car reference waveform. OKN was associated in all subjects with bilateral activity in the visual cortex, precentral and posterior median frontal gyrus (frontal eye field), prefrontal cortex, medial part of the superior frontal gyrus (supplementary eye field), posterior parietal cortex (parietal eye field), lateral occipitotemporal cortex, anterior and posterior insula, basal ganglia and thalamus. SPM data analysis enables us to demonstrate a three-dimensional representation of this sensorimotor network during OKN. Thanks to the use of Talairach co-ordinates a more precise localisation of activated areas, and a comparison with anatomical and neurophysiological data of primate studies was possible.