Slow and steady wins the baggage search

June 17, 2013, Duke University
Within this set of 32 figures, there is just one that forms a T shape. Professional searchers took longer to search patterns like this, but with higher accuracy than civilians. Credit: Adam Biggs, Duke University

Next time you're doing a slow burn in security screening at the airport, calm yourself with the assurance that a more deliberate baggage scanner may do a better job.

In a of visual searching ability, scientists found trained (TSA) screening officers were a lot slower than undergraduate students and other civilians. But the amateurs were sloppier.

The test is part of ongoing research by Duke University psychologist Stephen Mitroff to understand how the brain manages visual searching, which is important not only to security but also to . Adam Biggs, a postdoctoral associate in Duke's Center for , ran this series of tests on 206 TSA professionals based at Raleigh-Durham Airport (RDU) and 93 Duke undergraduates.

Participants performed an artificial search test on a computer screen n which they had to identify one particular T-shaped arrangement of two rectangles in a field of eight to 32 similar shapes. Half of the screens they looked at didn't include the correct shape.

Though not as complex or difficult as looking at real bags, the artificial test put the students and professional searchers on equal footing. "If we just showed undergrads real baggage images, they wouldn't know what to look for," Biggs said.

The researchers measured searchers' speed and accuracy over 256 tests per participant. They also split the TSA screeners in to two groups to distinguish those with less than 3 years experience and those with more than 6 years experience, but they didn't find any significant differences between them in basic screening abilities. Both TSA groups, who have been trained on how to search, outperformed the undergrads.

The students were 82 percent accurate at finding the target shapes, but on average only took 3.86 seconds per scan. The TSA searchers took longer—more than 6 seconds on average—but had accuracy rates of 87 and 88 percent.

The students also showed more variability in response time as the set of objects got larger; the professionals were more consistent.

Biggs said the professional screeners who took the test may be slower on the artificial task because their training makes them take more into consideration. Eye-tracking wasn't used in these experiments, but measures of their speed and consistency indicate it's likely the trained searchers were more systematic and methodical.

Earlier research by Mitroff's group and others has shown that memory plays an important role in searching. A slower, more consistent pattern of searching frees up some of the brain's processing, because the searcher doesn't have to remember what has already been examined. To experience the cognitive slowdown, Biggs suggests trying to recite the alphabet out of order. You slow down trying to remember which letters you've already used.

"We gain a lot by doing things consistently," Mitroff said. The takeaway for the Department of Homeland Security, which helped fund the research, is that training screeners to use methodical, consistent search patterns is the most effective way to improve performance. Biggs said that consistency by itself probably doesn't yield immediate benefits until a search pattern becomes second nature and doesn't have to be thought about, but they haven't measured that effect yet.

Explore further: Searching for tumors or handguns can be like looking for food

More information: The study appears online in Visual Cognition.

Related Stories

Searching for tumors or handguns can be like looking for food

August 7, 2012
If past experience makes you think there's going to be one more cashew at the bottom of the bowl, you're likely to search through those mixed nuts a little longer.

Anxious searchers miss multiple objects

June 15, 2011
A person scanning baggage or X-rays stands a better chance of seeing everything they're searching for if they aren't feeling anxious, according to a new laboratory experiment.

Videogamers no better at talking while driving

June 13, 2012
No matter how much time you've spent training your brain to multitask by playing "Call of Duty," you're probably no better at talking on the phone while driving than anybody else.

Video gamers really do see more, research says

June 11, 2013
Hours spent at the video gaming console not only train a player's hands to work the buttons on the controller, they probably also train the brain to make better and faster use of visual input, according to Duke University ...

Recommended for you

People with prosthetic arms less affected by common illusion

January 22, 2018
People with prosthetic arms or hands do not experience the "size-weight illusion" as strongly as other people, new research shows.

Study of learning and memory problems in OCD helps young people unlock potential at school

January 22, 2018
Adolescents with obsessive-compulsive disorder (OCD) have widespread learning and memory problems, according to research published today. The findings have already been used to assist adolescents with OCD obtain the help ...

Intensive behavior therapy no better than conventional support in treating teenagers with antisocial behavior

January 19, 2018
Research led by UCL has found that intensive and costly multisystemic therapy is no better than conventional therapy in treating teenagers with moderate to severe antisocial behaviour.

Babies' babbling betters brains, language

January 18, 2018
Babies are adept at getting what they need - including an education. New research shows that babies organize mothers' verbal responses, which promotes more effective language instruction, and infant babbling is the key.

College branding makes beer more salient to underage students

January 18, 2018
In recent years, major beer companies have tried to capitalize on the salience of students' university affiliations, unveiling marketing campaigns and products—such as "fan cans," store displays, and billboard ads—that ...

Inherited IQ can increase in early childhood

January 18, 2018
When it comes to intelligence, environment and education matter – more than we think.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.