Improved X-ray baggage screening sensitivity with ‘targetless’ search training

Abstract

When searching for a known target, mental representations of target features, or templates, guide attention towards matching objects and facilitate recognition. When only distractor features are known, distractor templates allow irrelevant objects to be recognised and attention to be shifted away. This is particularly true in X-ray baggage search, a challenging real-world visual search task with implications for public safety, where targets may be unknown, difficult to predict and concealed by an adversary, but distractors are typically benign and easier to identify. In the present study, we draw on basic principles of distractor suppression and rejection to investigate a counterintuitive ‘targetless’ approach to training baggage search. In a simulated X-ray baggage search task, we observed significant benefits to target detection sensitivity (d′) for targetless relative to target-based training, but no effects of performance-contingent rewards or the inclusion of superordinate semantic categories during training. The benefits of targetless search training were most apparent for stimuli involving less spatial overlap (occlusion), which likely represents the difficulty and greater individual variation involved in searching more visually complex images. Together, these results demonstrate the effectiveness of a counterintuitive targetless approach to training target detection in X-ray baggage search, based on basic principles of distractor suppression and rejection, with potential for use as a real-world training tool.

The label-feedback effect is influenced by target category in visual search

“…As a final note, the discovery that different formats of a label presented in conjunction with an object modulate the perception of the object and that such modulation is related to the type of category may be exploited for application to real-word situations. One such situation is X-ray baggage screening, the practice of visually checking X-ray images of baggage for threats and forbidden goods, a crucial component of airport security, that is open to effects of search strategies [ 120 ]. The use of an AV categorial label might be appropriate in this context (i.e.…”

Correction to: Improved X-ray baggage screening sensitivity with ‘targetless’ search training

“…The original article (Muhl-Richardson et al, 2021 ) mistakenly omitted some Declarations. These Declarations have since been re-introduced.…”