  We measured brain waves of viewers watching the 2D, 2.5D, and 3D motion
pictures, comparing them with one another. The relative intensity of
{\alpha}-frequency band of 2.5D-viewer was lower than that of 2D-viewer, while
that of 3D-viewer remained with similar intensity. This result implies visual
neuro-processing of the 2.5D-viewer differs from that of the 3D-viewer.
