Novel Methods for the Visualization and Analysis of Functional Maps in Cortex

Anatomy and Physiology 10 There are two dimensions of retinotopic organization: the eccentricity and angular (polar an- gle in Figure 3) dimensions (see Figure 3). The former can be described as follows. The poste- rior to anterior calcarine represents the foveal to peripheral visual field. The angular dimen- sion can be described by a path from the lower to the upper lip of the calcarine [Wandell, 1999 #16]. The area of the visual cortex that is devoted to the center of the visual field is much larger than the area that deals with information from the periphery of the visual field (Figure 4). Therefore, the retinotopic map is distorted to favor the fovea so that fine details can be seen in Figure 3: Retinotopic organization of visual areas A: Eccentricity and polar angle in the visual field; B: Eccentricity and polar angle in the cortex; F=fixation point, UVM=upper vertical meridian, LVM=lower verti- cal meridian, HM=horizontal meridian, C=Calcarine sulcus, PO=Parieto-occipital sulcus, CC=Corpus Callosum; See text for more details; Source: [Engel, et al., 1997 #21]