Inattentional Blindness Towards Important Objects in Visual Search

• Applicant: Dr. Daniel Ernst
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550309293

Visual search is a frequent task in everyday situations. When we search for our car at the parking lot, we usually proceed until we have found our car because we know that it must be there. Professional searchers like radiologists, however, often do not know whether there will be a single target, multiple targets or no target at all to be found. Especially when there is only limited time for a search (as in airport security screening, for instance), a target absent decision can be made prematurely, and a resulting miss error can have severe consequences. Furthermore, for professional searchers it is often important to notice unexpected but potentially relevant objects, which they were not originally looking for. For example, radiologists have to detect unexpected cancer (if visible) when they are originally searching for signs of pneumonia on a chest x-ray. On the one hand, previous research has shown that unexpected objects have a high potential to remain unnoticed even when retrospectively they are considered clearly visible. On the other hand, there is also research showing that unexpected objects have the potential to capture attention and the gaze. The first aim of this project is to investigate the conditions under which such an attention capture effect can facilitate the detection of an unexpected object. However, finding an unexpected but potentially important object may also result in a distraction from the original search target. Hence, the second aim is to examine how the encounter of an unexpected object affects the search accuracy for the original target. The third aim of this project is to investigate the attentional window– the region in the view field within which both targets and unexpected objects have the potential to be detected. Previous studies suggest that we can be blind towards objects that are not covered by the attentional window. However, to this date there are no established methods to measure the absolute size and the shape of the attentional window in order to predict miss errors. A novel approach that deals with issues of previous attempts is going to be established in the present project. Overall, insights into the project’s three research questions will help to understand how visual attention is allocated in search settings that bear the risk of missing important objects. Furthermore, the results provide a basis for the development of new methods to reduce miss errors in professional search settings.

• DFG Programme: Research Grants