Thus far, a commonplace observation. He had done a bit of research on it later and learned that the more sophisticated airports had hired psychologists to tackle the problem and devised some clever tricks. For example, they would digitally insert fake images of guns into the video feed from an x-ray machine, frequently enough that the screeners would see false-color silhouettes of revolvers and semiautomatics and IEDs glide across their visual fields several times a day, instead of once every ten years. That, according to the research, was enough to prevent their pattern-recognition neurons from being reclaimed and repurposed by brain processes that were more fruitful, or at least more entertaining.