Attentional enhancement opposite a peripheral flash revealed using change blindness

We describe a new method for mapping spatial attentionthat reveals a pooling of attention in the hemifield opposite a peripheralflash. Our method exploits the fact that a brief full-field blank caninterfere with the detection of changes in a scene that occur during theblank. Attending to the location of a change, however, can overcome thischange blindness, so that changes are detected. The likelihood of detecting anew element in a scene therefore provides a measure of the occurrence ofattention at that element's location. Using this measure, we mappedhow attention changes in response to a task-irrelevant peripheral cue. Underconditions of visual fixation, change detection was above chance across theentire visual area tested. In addition, a "hot spot" ofattention (corresponding to near-perfect change detection) elongated alongthe cue-fixation axis, such that performance improved not only at the cuedlocation but also in the opposite hemifield.