Investigating the role of feature integration demands on attention efficiency.

Feature integration and visual selective attention have been studied together to understand how we attend to different objects, often through conjunction search tasks. Conjunction search tasks involve searching for an object defined by multiple visual features in the presence of distractors. However, few studies have examined how different visual feature combinations impact search performance. Motivated by the functional and structural organization of the brain, this study investigated how differing feature combinations that theoretically place varying degrees of demand on feature integration impact attention efficiency. In two experiments, I explored reaction times (RT) and target detection sensitivity (d’) across varying set sizes and visual feature conditions thought to systematically target distinct visual processing pathways in the brain (i.e., color-motion, luminance-motion, and shape-color). My findings revealed that across both experiments, RT increased set size, indicating that search becomes longer with more distractors present. In Experiment 1, color-motion had slower RTs compared to luminance-motion. In Experiment 2, color-motion was less efficient than luminance-motion in target-absent only trials and the addition of motion as a relevant visual feature was associated with decreased search efficiency. These findings provide a better understanding of why some objects may be easier to find or harder to ignore and allow us to place certain visual selective attention abilities along a spectrum of efficiency, depending on which visual features are the target of attention. Future studies should explore neuroimaging techniques to understand the role of neural connections on integration of visual features within and across visual pathways.