Top-down guidance of eye movements in conjunction search.

We provide novel evidence for a two-stage model of visual search applied to the selection based on top-down cues to stimulus colour and orientation. The model supposes that visual displays are first parsed into colour based groups, a process that is modulated by the presence of an initial cue to the target's colour. Subsequently search is directed to other featural properties represented within the colour-based groups. Cues to the orientation of the target are only effective at this second stage. The results provide strong evidence that colour and orientation cues operate in different ways to guide search.