Fig. 17.

Implications of the orientation of intrinsic vibrissa curvature for the behaving rat. All schematics illustrate the same vibrissa at different points in time during protraction against an object. Arrow indicates direction of protraction. A: CB collision of a vibrissa with a point object. As the vibrissa protracts, the vibrissa becomes more convex to slip past the object. B: CF collision of a vibrissa with a point object. As the vibrissa protracts, it first straightens. Next, the vibrissa tip bends backwards to permit the vibrissa to slip past the object. C: CF collision with a wall. As the vibrissa protracts, the tip is first to strike the surface. This may provide an initial “spike” in axial force before general deformation of the vibrissa.