Fig 7. Whiskers are conformed onto the universal Euler spiral.

(A) The heavy gray line indicates a universal Euler spiral. A total of 225 whiskers from four rats are conformed onto this spiral and vertically offset so that they can be visualized clearly. Color indicates whiskers from four different rats. (B) Left: Whiskers are mapped onto the Euler spiral and sorted (vertically offset) by their row identity. The conformed whiskers overlap almost completely (distinguishable only by the offset), indicating that the mapping shows no correlation to whisker row identity. Right: The mean position of the whisker on the Euler spiral is plotted as a function of row. (C) Identical to B, but for column identity instead of row identity. Again, the mapping shows no correlation to whisker column identity. (D) Left: Whiskers are sorted (vertically offset) by their arclength and mapped onto the Euler spiral. The grayscale matches the color of the arc length indicated in the right panel. Right: Each vertical line shows the span of the whisker conformed on the universal Euler spiral. No correlation is observed between arc length and either the mean location or the span of the whisker on the Euler spiral. (E) Identical to (D), but for average whisker curvature instead of arc length.