Global feature-based attention for motion and color

AbstractWe used a divided attention psychophysical task to test the hypothesis that visual attention to a stimulus feature1We define a ‘feature’ as a property within a stimulus dimension. For example, upward and downward directions of motion are two opposing features within the stimulus dimension of motion, and red and green are opposing features within the stimulus dimension of color.1 facilitates the processing of other stimuli sharing the same feature. Performance on a dual-task was significantly better when human observers divided attention across two spatially separate stimuli sharing a common feature (same direction of motion or same color) compared to opposing features. This attentional effect was dependent upon the presence of competing stimuli. These results are consistent with a spatially global feature-based mechanism of attention that increases the response of cortical neurons tuned to an attended feature throughout the visual field