Figure 2.

Analytical 2D mapping of the visual stimuli onto cortical space. A, An example of a stimulus as seen in the visual field, shown here against a polar grid. B, Enlargement of the stimulus zone in A. C, The stimulus zone in B after applying the analytical spatial transformation. D, Top, A series of intrinsic imaging activation patterns evoked by a vertical bar (0.25 × 6°) separately presented at different locations parallel to the LVM: LVM −0.5°, LVM −1.5°, VM −2.5° (−, to the left of LVM in the contralateral hemifield). Bottom, A series of activation patterns evoked by a horizontal bar (6 × 0.25°) separately presented parallel to the HM: HM −2.5°, HM −3.5° (−, below HM). Insets, Stimulus positions relative to the fixation point (red dot). E, Image of the blood vessel pattern in V1 taken on one VSDI experiment. The solid red lines mark the retinotopic mapping of the Cartesian lines shown in D. Dashed red lines, the borders between V1 and V2 and the LUS; black asterisks, two anchor points used for image registration; black dots, six points for optimizing the model's fit (see Materials and Methods; note, the intrinsic imaging recording and the VSDI recording were done on separate imaging days, therefore due to the relative angle between the camera and the cortical surface the blood vessels may seem slightly shifted between D and E). F, The spatially transformed stimulus (from C) after image registration on the exposed cortical surface. LUS, lunate sulcus; UVM, upper vertical meridian; LVM, lower vertical meridian; HM, horizontal meridian, A, anterior; P, posterior; M, medial; L, lateral.