Fig. 1.

Two protocols were tested. A: braking protocol. The animal was rotated back and forth continuously in ∼300° sweeps and then stopped either at the cell's preferred firing direction (PFD) or 90° counterclockwise (CCW) to the cell's PFD. B: static placement protocol. The animal was placed in a stationary position for 30 s at eight equidistant directions around 360°, starting at the cell's PFD. At each position, the cell's response was recorded while the animal was in a motionless state. The major difference between the two protocols was in terms of the type of motion experienced by the rat prior to its static placement in a particular orientation. In the first protocol, the rat experienced 30 s of back-and-forth motion in the horizontal plane, while in the second protocol the animal experienced only a short 45° rotation over ∼1 s prior to placement at a static position.