Asymmetric Hemispheric Activations during 10° Lateral Gaze (fMRI Study)

Functional MRI was used to study the differential effects of the direction of gaze on the visual and the ocular motor systems. Fixation of a target straight ahead was compared to fixation of a target 10° to the right and 10° to the left, and to eyes open in complete darkness in thirteen healthy volunteers. BOLD signal increases in fronto-parietal ocular motor and attentional structures were absent during central fixation eyes open and minimal during lateral fixation eyes open, which confirmed the earlier finding that these structures are already activated with open eyes in darkness. During lateral fixation, acti…