Fig. 1.

The setup and the behaviors. From left to right the unique behaviors, stand still, walk, skip, and jump while fixating the target (note that the stand still behavior was conducted twice). The target consisted of a green disk placed on a microphone stand (height 0.87 m and placed at a distance of 1.65 m). To enable the observers to walk and skip around the target, we marked with duct tape a circle with a radius 1.65 m on the floor