Applying Psychology to Visual Searches for Security Threats in War Zones and High-risk Public Spaces
Submitting InstitutionUniversity of Southampton
Unit of AssessmentPsychology, Psychiatry and Neuroscience
Summary Impact TypeTechnological
Research Subject Area(s)
Information and Computing Sciences: Artificial Intelligence and Image Processing
Summary of the impact
Researchers at the University of Southampton have informed aviation
security policies and training
procedures of soldiers in the USA and UK. The research has applied
principles from vision science
to the practical field of contemporary security, specifically the
screening of airport baggage for
weapons and explosives, and the search for Improvised Explosive Devices
(IEDs) embedded in
the environment in combat theatres such as Afghanistan. Findings have
contributed to international
airport security and to vital training for troops in combat situations.
They have also been widely
used to inform the public about the latest advances in security
Academics at the Centre for Vision and Cognition (CVC) have applied
principles from vision
science and the human attention system to the practical field of
contemporary security, specifically
the screening of airport baggage for weapons and explosives, and the
search for Improvised
Explosive Devices (IEDs) embedded in the environment in combat theatres
such as Afghanistan.
Research into the way airport security staff view X-ray images of
passengers' baggage began
shortly before the 9/11 attacks in the United States in 2001. With funding
from the US Department
of Homeland Security [3.G1], the UK Department of Transport, private
defence firm QinetiQ and
the EPSRC [3.G2], Professor Nick Donnelly (Head of Psychology), Professor
Kyle Cave, (Reader
in Psychology, 1999-2003) and Dr Tamaryn Menneer (Lecturer in Psychology)
search for two different objects at the same time. This situation reflects
a baggage screener's
search for potential threats from metal weapons (guns or knives), which
appear in blue on baggage
scans, or IEDs, which appear largely orange.
Results [3.1] showed that conducting two single-target searches is more
efficient than carrying out
a dual-target search, concluding that the need for baggage screeners to
search simultaneously for
very different targets (guns, knives and IEDs) could result in
inefficiencies. Building on these
results, the CVC team confirmed [3.2, 3.3, 3.4] that a dual-target search
for dissimilar targets
reduces accuracy, suggesting that dividing search tasks for X-ray baggage
Further research [3.5, 3.6] revealed that conducting searches for two
targets when one appears at
a higher prevalence level than the other will result in the
higher-prevalence target being detected
often, at the expense of the lower-prevalence target. This finding exposed
a potential weakness in
current airport security screening policy, where screeners search for both
bottles of liquid, which
are frequently occurring, and threat items, which occur rarely.
The findings proved of interest to the Ministry of Defence's Counter
Terrorism Centre (CTC), as it
sought to improve efficacy of visual searches for IEDs by troops in
Afghanistan, the main cause of
casualties in combat. The Defence Science and Technology Laboratory (Dstl)
and the CTC
provided funding [3.G3] to explore how to improve detection of threats in
environments beyond X-ray environments [5.1-5.4]. Full details of these
projects cannot be
disclosed due to their security-sensitive nature but analyses of eye
movement behaviour, attention
allocation, and underlying decision processes displayed by soldiers, both
experienced in finding
IEDs and those new to the task, gave rise to recommendations for new
The MOD is now applying the threat detection techniques developed for
British troops in
Afghanistan to security procedures closer to home, by funding the CVC team
for on-going work to
develop and test a training framework for searches of public spaces and
The CVC team has also been awarded funding by the Economic and Social
(ESRC), under the RCUK Global Uncertainties programme, for on-going
research on whether 3-D
depiction of X-ray-image objects helps the search for possible security
References to the research
3.1 Menneer, Tammy, Phillips, Luke, Donnelly, Nick, Barrett, Doug J.K.
and Cave, Kyle R.
(2004) Search efficiency for
multiple targets. Cognitive Technology, 9, (2), 22-25.
3.2 Menneer, Tamaryn, Barrett, Doug J.K., Phillips, Luke, Donnelly, Nick
and Cave, Kyle R.
2007) Costs in searching for
two targets: dividing search across target types could improve airport
security screening. Applied Cognitive Psychology, 21, (7), 915-932.
3.3 Menneer, T., Cave, K. R., & Donnelly, N. (2009). The cost of
searching for multiple targets:
Effects of practice and target similarity. Journal of Experimental
Psychology: Applied, 15,
3.4 Stroud, M. J., Menneer, T., Cave, K. R., & Donnelly, N. (2012).
Using the dual-target cost to
explore the nature of search target representations. Journal of
Human Perception and Performance, 38, (1), 113-122.
3.5 Godwin, H. J., Menneer, T., Cave, K. R., Way, R. L., Helman, S.,
& Donnelly, N. (2010).
The impact of relative prevalence on dual-target search for threat items
from airport X-ray
screening. Acta Psychologica, 134, 79-84.
3.6 Menneer, T., Donnelly, N., Godwin, H. J., & Cave, K. R. (2010).
High or low target
prevalence increases the dual-target cost in visual search. Journal of
Psychology: Applied, 16, 133-144.
3.G1 Donnelly, N. & Cave, K. R. July 2002 — June 2008. "Improving the
efficiency of visual search:
Single-target versus dual-target search". $490,324. Transportation
Security Laboratory, U.S.
Department of Homeland Security.
3.G2 Donnelly, N. October 2005 — September 2008. PhD studentship: "Visual
search for threat
items in airport security screening." £70,000. QinetiQ, Department of
Transport and EPSRC.
3.G3 Donnelly, N. & Liversedge, S.P., June 2010 — current. "Threat
detection in complex
environments". £242,000, Defence Science and Technology Laboratory (Dstl)
Counter Terrorism Science and Technology Centre (CTS & TC).
3.G4 Donnelly, N. & Garner, M.J., October 2013 — October 2016. PhD
studentship "The role of
cognitive neuroscience in understanding, managing and optimising human
£101,517, Defence Science and Technology Laboratory (Dstl).
3.G5 Garner, M.J., Godwin, H., & Hadwin, J.A., October 2013 — October
2016. PhD studentship
"Understanding, managing and optimising human performance when engaged
visualisation displays". £85,502, Defence Science and Technology
3.G6 Donnelly, N., Menneer, T. & Liversedge, S.P., November 2011 —
November 2015. "Teaching
the visual system to segment and interpret images of overlapping
Details of the impact
Research results actively disseminated by CVC academics have influenced
and defence strategies employed by the Ministry of Defence (MOD), the US
Homeland Security (DHS), the Department for Transport and private defence
The work on detecting IEDs in combat zones is directly informing current
training in Counter-IED
procedures and is helping to build the capability of Britain's armed
forces by tackling the main
cause of casualties in the combat theatre. In 2009 USA Today reported that
75% of coalition
casualties in Afghanistan were caused by IEDs, up by 50% on 2007. The
CVC's findings [5.2-5.4]
are being used to inform military personnel in combat zones and the MOD
has forwarded the
research to army commanders and private contractors in the field. The
MOD's Counter Terrorism
Centre acknowledged the value of the research as follows by email [5.1]:
"The outputs from the studies conducted by the University of
Southampton have been presented to
a range of stakeholders, as well as informing the understanding of the
mechanisms that underpin
the visual search for targets in an operational environment.
Presentations using the findings of
these studies have been given to the following: [RESTRICTED TEXT
Donnelly acted as one of the advisors to the Dstl's `Tiger' IED detection
team in 2010. In December
that year, Dstl released a statement describing the "success" of
the Tiger team in developing new
technologies to detect IEDs in Afghanistan. The team, comprising the MOD,
and Support (DE&S), military and industry, demonstrated the "viability
of four exploitable solutions
which are being transitioned to DE&S for final development and
procurement." The statement also
said that the success of the Tiger team would inform the MOD's research
strategy. Over recent
years (2010-2013) the number of deaths from IEDs for UK troops has
reduced. There are multiple
reasons for this reduction, including better detection of IEDs, which has
been informed by the
research from Southampton.
Further to this successful project, the MOD is drawing on the research of
team to train security personnel in identifying threats in public spaces
such as conference centres
and private homes [3.G3]. The results of this on-going research [5.4] will
be used to develop and
inform training for high-level security procedures at, for example, public
and VIP national and
The findings on X-ray screening of airport baggage [5.5-5.8] led the DHS
to test them in the field
on US airport baggage screeners. The work is now informing airport
security policy. Dr Josh
Rubinstein of the DHS' Transportation Security Laboratory [5.5] says the
CVC team "has been
instrumental in supporting the Department of Homeland Security's
research program on aviation
security. The research has greatly enhanced our understanding of the
perceptual and cognitive
processes involved in airport security x-ray visual search." He
continues, "your work is finally
bubbling up to affect policy."
CVC researchers have also disseminated research findings to the
international aviation security
industry, presenting results at the Fourth International Aviation Security
and the International Transport Security Human Factors Technical Advisory
The research has informed a wider audience through publication in the
press and broadcast
media, including a film report by the Associated Press news agency for
distribution to over 500 TV
channels worldwide. The findings on dual-target search were conveyed to
the general public at the
Royal Society Summer Science Exhibition (London, July 2011) [5.9],
attended by around 14,000
people. Interactive displays involved visitors having their eye movements
tracked as they searched
for guns and IEDs in baggage X-rays. Visitor questionnaires showed strong
support for the
statement, "After visiting this stand I think that psychology research
makes a valuable contribution
to life in the UK." The BBC, The Guardian, China Radio International
and various weblogs covered
the involvement of the research in the exhibition [5.10]. Menneer was
interviewed by radio station
Radio Wave 105.
Sources to corroborate the impact
5.1 Ergonomist — Human Integration Team, Defence Science and Technology
Selected reports to DSTL:
5.2 Godwin, H. J., Kirkby, J., Liversedge, S. P. L., & Donnelly, N.
expertise for IED detection in the visual environment. Research Report to
Sciences Technology Laboratory (Dstl).
5.3 Godwin, H. J., Liversedge, S. P. L., & Donnelly, N. (2011). Eye
Movements and Visual
Search for Threat in the Environment. Research Report to Defence Sciences
5.4 Donnelly, N., Mann, C. M., Godwin H. J., & Liversedge S. P.
(2012). Eye Movement
Behaviour during Building Search. Technical Report to Defence Sciences
Department of Homeland Security corroborator:
5.5 Chief, Army Research Laboratory, Human Research and Engineering
Selected reports to DHS:
5.6 Donnelly, N., Menneer, T., Butler, C., Cave, K. R., Li, X., Stroud,
M. J, and Rubenstein, J.
June 2008. Search for multiple threat items is less effective than
report to U.S. Department of Homeland Security, Transportation Security
5.7 Donnelly, N., Menneer, T. and Cave, K. R. March 2009. Dual-target
Summary of research (2002-2009) and Contribution to the Academic Research
for Josh Rubenstein, U.S. Department of Homeland Security, Transportation
5.8 Menneer, T., Donnelly, N. and Cave, K. R. February 2010. Increasing
the efficiency of
airport security screening: A review of publications. Reported to Josh
Department of Homeland Security, Transportation Security Administration.
Royal Society Summer Science Exhibition corroborator and weblinks:
5.9 Events Officer, The Royal Society.
5.10 Links to example Exhibition material: