Color dominates! The importance of color in attentional templates for target objects in visual search.
43.4085, Monday, 18-May, 8:30 am - 12:30 pm, Pavilion
Rebecca Nako1, Tim Smith1, Martin Eimer1; 1Department of Psychological Sciences, Birkbeck, University of London
Attentional templates guide the selection of target objects in visual search. The efficiency of template-guided target selection can be determined by measuring the N2pc component of the event-related brain potential. When word cues specify the target object for three subsequent search displays, the N2pc is delayed for the first search display after the cue relative to the second and third display, demonstrating that word cues are insufficient to fully activate target object templates (Nako et al., in press). We conducted two experiments to determine how the acquisition of target templates is affected by color. Word cues (e.g., “apple”) were followed by three search displays that each contained the cued target together with three distractor objects. In Experiment 1, grayscale or colored search displays were shown in different blocks. In Experiment 2, cued trial runs of search displays with grayscale or colored objects were presented in a random unpredictable sequence. In both experiments, N2pc components were delayed for the first relative to two subsequent displays in each trial run. The N2pc for the second and third display emerged earlier on trials with colored objects relative to trials with monochrome objects, demonstrating that color information facilitates target selection once a target object has been encountered at least once. There was no such facilitation by color for the display that immediately followed the cue in Experiment 1 where participants knew in advance that either colored or grayscale objects would be shown. However, when color and grayscale trial runs were mixed and thus unpredictable, the N2pc to the first display emerged earlier when it contained colored objects, indicating that color was included by default in the attentional templates set up in response to word cues. These results show that color information plays a central role in the guidance of object selection by attentional templates.