Designing beyond the video wall: serial processing as a cognitive principle for surveillance interfaces

Security surveillance operators face a volume of visual information incompatible with the limitations of cognitive processing. Traditional multiplex interfaces present multiple camera feeds simultaneously, assuming that broader visual access enhances threat detection. Yet cognitive research shows that visual processing is serial: only a limited subset of information can be processed in depth at any given moment. Using a surveillance microworld, we compared a conventional multiplex interface against a monoplex interface that supports serial processing by displaying a single camera feed at a time. A total of 128 participants completed four 8-min scenarios comprising incidents that varied in saliency, duration, severity and specificity. Although incident detection did not differ between interfaces, the monoplex condition significantly improved situation awareness with no increase in perceived workload. These findings challenge the simultaneous visual access assumption underlying prevailing surveillance design and support a cognitively grounded approach that supports cognitive fit rather than information availability.