Selected Column
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Click a column to see its preferred orientation
Orientation Color Map
0°45°90°135°180°
Orientation columns in V1 are ~50 μm wide vertical slabs of neurons all preferring the same edge direction. Neighboring columns prefer similar orientations, rotating ~10°/column. Around each pinwheel singularity (center), all orientations 0–180° are represented in one full rotation. The inter-singularity spacing is ~700 μm (one hypercolumn). Hubel & Wiesel discovered these columns in 1962, winning the 1981 Nobel Prize.
Pinwheels come in two chiralities: clockwise (+) and counterclockwise (−). They arise through symmetry-breaking during development, described by Gaussian random fields. The density of singularities is approximately 1 per mm².