How do I look?

Our vision isn’t as good as we think it is. Whether you have 20/20 vision or need a bit of help, the amount of visual information we can absorb with our eyes is limited – and our brains fill in the missing parts.

The Centre for Perception and Cognition runs an eye tracking laboratory with four state-of-the art Eyelink 1000 eye trackers in its laboratories.

Pioneering eye tracking research at Southampton is exploiting our eyes’ limitations to offer new, more effective methods for visual search tasks such as airport baggage screening, crime scene searches, explosives detection in war zones and spotting suspicious behaviour in crowded public spaces.

Psychology researchers from the University’s Eye Movement Research Unit, who are leading the research, have worked with Government departments, security professionals and the military to better understand how people look for things.

Dr Hayward Godwin, Associate Professor in Psychology and member of the Centre for Perception and Cognition (CPC), is an expert in the field. He said: “Our vision is not as good as we think it is. We have to really look at things to work out what they are. Our eyes give us the impression that everything is nice and clear, but really it is our brains filling in the details. Eye tracking exploits this. If you watch what someone’s eyes are doing, you can work out what they are interested in and what information they are trying extract from the world around them.”

The CPC runs an eye tracking laboratory with four state-of-the-art Eyelink 1000 eye trackers in its laboratories. The eye trackers can be taken to different venues, in the customised mobile research unit, for data collection.

The team has conducted research funded by the Government’s Defence Science and Technology Laboratory (Dstl), the Ministry of Defence (MOD), the Department for Transport and the Home Office – all to better understand how we search.

Suspicious minds Countering modern-day terrorism by spotting suspicious behaviour in crowded venues was the focus of a project funded by the Home Office’s Defence and Security Accelerator.

Hayward explained: “In this project, instead of having more security staff and equipment to seek out threats, it’s about trying to train members of the public to be good at spotting suspicious behaviour. An example is the British Transport Police’s campaign, See it. Say it. Sorted.”

The CPC team compiled training materials, audio announcements and videos about spotting suspicious behaviour and threats in public places. They also ran experiments and focus groups using the new training materials. The findings were supported by eye movement examinations of people searching for threats in crowded public spaces.

For further information, visit: www.southampton.ac.uk/psychology

Dr Hayward Godwin and Dr Stuart Pugh using the eye tracking equipment in the Eye Movement Research Unit

Safe as houses How would you go about searching a house for evidence of a bank robbery? Former CPC PhD student Dr Charlotte Riggs conducted an experiment, funded by Dstl, to find out how trained soldiers’ search methods differed from those of the lay public.

Charlotte, who now works as a lecturer at the Royal Military Academy in Sandhurst, set up an empty house in Southampton to look as if it were lived in. She and a team of students scoured charity shops for furniture and items to kit out the house, then hid paraphernalia such as drugs, cash and guns.

Hayward explained: “Seventy-four participants wore head-mounted eye trackers, and we had participants working in teams looking for items related to a bank robbery. Using the eye tracking devices, we assessed how careful people were when they were searching. Did they strip back cupboards and go through boxes of food, and so on?

“We compared the methods of the soldiers with how the undergraduates – who weren’t trained in searches – tackled the search. We found, as expected, that the undergraduates weren’t as systematic and thorough as the military personnel and that, therefore, the training given to these personnel is effective.”

Patrol safety Another Dstl-funded project conducted with the military was an eye tracking study in Afghanistan in 2015.

The project team examined the influence of experience on the decisions made by military personnel as they conducted risk assessments of scenes photographed from patrol routes during the conflict in Afghanistan.

Participants were asked to decide whether it would be safe to continue patrolling through the route shown, and the responses of experienced personnel versus those who had only done the basic training were compared – along with their eye movements.

The project report states: “We found that both participant groups were equally likely to fixate Potential Risk Indicators (PRIs), demonstrating similarity in the selectivity of their information-sampling. However, the inexperienced participants made more revisits to PRIs, had longer response times, and were more likely to decide that the scenes contained a high level of risk. These results suggest that experience primarily modulates decision-making behaviour.”

Airport baggage Baggage security scanning, such as at airports, is another focus for the CPC.

“If you show a computer screen to someone and don’t record their eye movements, you don’t know what they have looked at,” said Hayward. “If they say something isn’t there, we don’t know how they have managed to miss it. If a target like a gun is present but someone says they cannot find it, is it because they haven’t looked at it, or is it because they have looked at it but failed to detect it?”

Tracking eye movement behaviour can be used to answer this.

Hayward added: “In real tasks, like at airports, it’s very rare for actual threats to appear. We have done a lot of work around eye tracking and how people tend to subconsciously give up on things that do not very often appear.”

Another element to this is colour. “In airports, baggage screening operators are asked to look for guns, which are orange, and knives that are blue,” said Hayward. “We, as humans, are naturally not good at doing this – if we are asked to look for more than one colour, we are terrible at identifying either.”

Looking to current and future work building on this, Hayward added: “The team also has an ongoing project looking at current policy and procedures in UK airports. This has been delayed due to the pandemic but has now begun working again.”