Cerebral Cortex Advance Access originally published online on February 27, 2008
Cerebral Cortex 2008 18(11):2586-2595; doi:10.1093/cercor/bhn016
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The Intrinsic Shape of Human and Macaque Primary Visual Cortex
1 Department of Cognitive and Neural Systems, Boston University, Boston, MA 02215, USA, 2 McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, 3 Department of Radiology, Massachusetts General Hospital, Athinoula A. Martinos Center, Harvard Medical School, Charlestown, MA 02129, USA, 4 Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA, 5 Department of Neurology, Massachusetts General Hospital, Athinoula A. Martinos Center, Harvard Medical School, Charlestown, MA 02129, USA, 6 Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA, 7 Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02215, USA
Address correspondence to Oliver Hinds, McGovern Institute for Brain Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 46-5081, Cambridge, MA 02139, USA. Email: ohinds{at}mit.edu.
Previous studies have reported considerable variability in primary visual cortex (V1) shape in both humans and macaques. Here, we demonstrate that much of this variability is due to the pattern of cortical folds particular to an individual and that V1 shape is similar among individual humans and macaques as well as between these 2 species. Human V1 was imaged ex vivo using high-resolution (200 µm) magnetic resonance imaging at 7 T. Macaque V1 was identified in published histological serial section data. Manual tracings of the stria of Gennari were used to construct a V1 surface, which was computationally flattened with minimal metric distortion of the cortical surface. Accurate flattening allowed investigation of intrinsic geometric features of cortex, which are largely independent of the highly variable cortical folds. The intrinsic shape of V1 was found to be similar across human subjects using both nonparametric boundary matching and a simple elliptical shape model fit to the data and is very close to that of the macaque monkey. This result agrees with predictions derived from current models of V1 topography. In addition, V1 shape similarity suggests that similar developmental mechanisms are responsible for establishing V1 shape in these 2 species.
Key Words: correlated variability • cortical area development • myelin • striate cortex • visual topography