The software used was developed on Adobe® FlexTM platform. It ran on a Lenovo ThinkPad with the resolution set at 1280 × 800 pixels and a refresh frequency of 60 Hz. The computer was connected with the LCD by a data line. Participants were seated on an adjustable chair before the screen at a distance of 800 mm. The height was adjusted so that the participants’ eyes were at the same height as the center of the screen.