Non-invasive methods are required to investigate the human brain. Visual stimuli elicit visual evoked scalp potentials (VEPs) which can be recorded from electrodes attached to the surface of the scalp. These VEPs are generated by current sources located in the brain. The location of these neural sources can be estimated when a a source is modeled as a dipole and the head is modeled as three concentric spherical shells representing the scalp, skull and neural tissue. This model is know as dipole source localization.
A series of experiments were carried out using a red-green chromatic grating stimulus and visual evoked potentials were recorded. I will present dipole source localization results from this stimulus which was presented in various positions in the visual field. I will also present results that demonstrate how incorporating anatomical information from MRI scans can improve localization results.