Abstract
Sometimes objects are not where you expect them, but sometimes objects can be found where ever: think of a cat. In the current study, we investigated the effects of the variability of spatial associations between objects and scenes. Based on the Surface Guidance Framework, during search attention is deployed to relevant scene surfaces at a specific vertical position in the scene (i.e., upper, middle and lower surfaces; Pereira & Castelhano, 2019). However, as strength of the spatial associations between objects and scene are variable, the focus of attentional deployment may vary with it.
In the current study, we examined the effect of the expected spatial variability of target objects on search performance. For each trial, participants’ eye movements were tracked while they searched for one of two types of target objects: (1) Fixed Targets, which were associated with a specific surface (animal head mount, flower vase, boots); (2) Variable Targets, which were not associated with a specific region (fan, basket, cat).
Results showed not only a slower reaction time for variable than fixed targets, but also an interesting pattern across eye movement measures. Attentional guidance measures showed longer times and many more fixations to get to variable than fixed targets. Interestingly, differences were not immediately apparent as the direction of the first saccade and fixations to the relevant scene region did not differ. When looking at the pattern of fixations over the course of the trial, the differences were apparent during the latter half of the search trial. This suggests that the influence of spatial expectations for variable vs. fixed targets on attentional deployment may not be immediate. We will further explore the deployment of attention over the course of the trial to address these differences in strategy implementation.