Fig. 1.

Experimental setup. A: schematic showing top view (top) and side view (bottom) of track. Rat runs from left to right through the grating-lined area of the track while the camera acquires video and then breaks an infrared trigger beam that signals the camera to send frames to computer. Rat and vibrissae are backlit with red LED array that shines through the glass diffuser floor of the grating-lined area of the track. B: single frame showing head and whisker tracking from high-speed video in which the head (triangle defined by white dots), reference vibrissa (short spline, left side of face), and a full vibrissa (longer spline, left side of face) are being tracked. See the corresponding movie file in the Supporting Information (WhiskerTrackingMovie.mov) for the full sequence. Inset: magnification of the spline tracking of a vibrissa in contact with the grating and a short reference vibrissa, highlighted with the white curves.