Searching for an item in dynamic visual environments : Impact of a moving background on visual search
Résumé
Many interactive virtual environments such as video games include complex visual displays where various objects are shown superimposed on a moving background. Thus, the main goal of this study was to assess the impact of a moving background, which triggered an optokinetic nystagmus, on visual search for simple objects. A typical visual search paradigm was used. Forty-two participants had to detect the presence/absence of a geometrical shape among 3, 6 or 9 other shapes on a computer screen. The shapes were shown on a patterned visual background [Tozzi et al, 2007, Vision Research, 47, 861-868] that could either be still or move from right to left at a 12 cm/s velocity. The participants’ eye movements were recorded with a Tobii T120 eye tracker. Search accuracy was decreased by the moving background when the target was present in the 9 items condition. However, there was no significant difference in response times between the two background conditions. The eye tracking data demonstrated that background movement modified the location of the first eye fixation on the search display, which was located more rightwards than when the background was still. Further research is needed to clarify the impact of moving backgrounds on visual search.