Top-down modulation of visual attention

This body of work examines the effects of pre-cues on visual search for targets defined by a colour-orientation conjunction. Cueing the identity of targets enhanced the efficiency of search, with stronger effects from cueing the colour of the target compared to cueing its orientation, even though the targets were balanced for search efficiency within both orientation and colour dimensions. The colour advantage remained when the response to the target was task-irrelevant and occurred whether information was presented as visual cues or verbal cues. There was, however, evidence of automatic priming from the physical nature of cue stimuli playing a substantial role in guiding search, particular when based on the cue’s colour. Eye movement data from uncued trials indicated fixations were initially directed to a subset of items with the same colour. Cues were assumed to direct fixations within this colour-grouped array. Colour cueing effects reinforced the parsing of stimuli grouped by colour, while orientation cues enhanced local orientation disparities within the colour groups. The findings suggest that the advantage for colour cueing may be due to a combination of more efficient early segmentation of search items into colour groups and stronger grouping arising within these groups