Fig. 2.

Example of “face to face” behavior observed using the side and upper camera. The first picture indicates the starting of spinning and is set to 0 sec. Reaching behavior was performed after the end of the spin, and at the moment when the mouse touched the pasta, the observer's behavior was classified into the following three categories: “face to face,” “ambiguous,” or “not paying attention.” The “face to face” behavior is defined as the two heads being in a straight line at the time of reaching behavior.