Aviation securityAnxious Searchers Miss Multiple Targets
Research shows that when people search for objects — say, air port security personnel screening baggage for weapons — they typically miss the second of two objects once they find the first one; missing a second target is a well-known issue called “satisfaction of search,” and it manifests itself in both airport screening and looking for cancerous tumors in a lab; now researchers find that anxiety heightened the satisfaction-of-search problem
A person scanning baggage or X-rays stands a better chance of seeing everything they are searching for if they are not feeling anxious, according to a new laboratory experiment.
Duke psychologists put a dozen students through a test in which they searched for particular shapes on a computer display, simulating the sort of visual searching performed by airport security teams and radiologists.
Stephen Mitroff, an assistant professor of psychology and neuroscience who led the experiment, says this area of cognitive psychology is important for improving homeland security and healthcare. He has begun collaborating with the Transportation Security Agency (TSA) at RDU airport and radiologists at Duke.
A duke University release reports that in earlier studies of this type, Mitroff’s team had wondered whether the anxiety produced by being visible to a long line of frustrated travelers or having to interpret an image in a medical emergency might change a person’s performance on these sorts of tasks.
To simulate a stressful situation in this study, the researchers told the participants they might receive an unpredictable electrical shock for half of the trials that would be unrelated to their performance. Annoying but not painful electrical shocks are a well-established means of inducing anxiety in the lab. Only tests run without a shock were analyzed, focusing the research on the anxiety produced by anticipating a negative event. On the other half of the trials, participants heard a harmless tone.
Subjects performed about the same when searching for a single object whether anxious or not. When the researchers added a second target, however, participants were more likely to miss the second object when anxious, despite spending the same amount of time looking at the image.
Missing a second target is a well-known issue called “satisfaction of search,” Mitroff said, and it is believed to account for about 40 percent of radiology misses. A person finds the first object and then simply fails to see the second one, even though they are still looking.
Anxiety heightened the satisfaction-of-search problem, a finding which has important implications for the way we train and test searchers, Mitroff said.
The research appear early online 13 June in Psychological Science. It was supported by the Army Research Office and the Institute for Homeland Security Solutions.
— Read more in Matthew S. Cain et al., “Anticipatory Anxiety Hinders Detection of a Second Target in Dual-Target Search,” Psychological Science (13 June 2011) (doi: 10.1177/0956797611412393)
