Illustration of required reference frame transformations.

Spatial information presented in screen 1 and 2 is integrated within the reference frame of screen 1 (top), screen 2 (middle), or screen 3 (bottom). Regardless of which reference frame participants integrated, they always reacted on the integrated layout in screen 3. Arrows indicate required transformations. Transformation costs for dotted arrows might be negligible due to updating or sufficient time.