Retinotopic Mapping

Retinotopic mapping is the mapping of visual inputs from the retina to neurons in the visual cortex and related structures.

Mapping of the visual system in humans can be performed using functional magnetic resonance imaging. Checkerboard-like stimuli are presented and flashed at changing positions in the visual field, typically in a cyclical manner. Unifield stimulation has been used traditionally, where a single wedge of checkerboard is rotated. Bifield stimulation involves two checkerboard wedges that mirror each other and rotate in a propeller-like manner, and has been shown to reduce acquisition time by almost half when compared to unifield stimulation (Slotnik and Yantis 2003). This stimulates activity in different visual areas of the brain, like V1 and V2 (Engel et al. 1997).

Surface-based registration is the classification of different brain tissues and segmentation of grey matter, inflation of the grey matter to a sphere, and the alignment of these spheres based on major brain...