Visual Search Strategy in a Virtual Reality Supermarket: The Effects of Scene Familiarity, Age and Sex on Eye Fixation Distribution

Abstract

Introduction: Virtual reality (VR) environments enable the simulation of real life situations, while being easily controllable and adaptable. Their ecological validity is high and they are well suited for use in neuropsychological diagnosis and assessment. For this, reliable norms will have to be developed, based on the behavior of healthy people inside those virtual environments. Visual search strategy plays a role in visual perception and is an example of such behavior. When better understood, it could be used as an indicator of cognitive and behavioral (dys)function. The aim of this study was to assess visual search strategy by examining the distribution of eye fixations in space. Methods: Visual search strategy of healthy people was studied using eye tracking data from participants in the Virtual Supermarket Task (VST). The eye fixation distribution over the rows of aisles in a virtual supermarket was analyzed, using the number of fixations and fixation duration per row. Results: Participants fixated longer on higher and middle rows compared to lower rows, and fixated more on the higher rows, compared to the lower rows. Visual search strategy in pathways with target products was skewed towards the higher rows. Conclusions: The established differences between visual search strategy in target and nontarget pathways should be considered in future use of the eye tracking data of participants in the VST. However, no corrections seem to be necessary for the age and sex of participants.