Characteristics of attention and visual short–term memory: implications for visual interface design

Although the human retina can code many object images simultaneously, observers are often aware of only a tiny fraction of this information. These processing limitations of the visual brain have evolved to prioritize particularly relevant features of a scene while ignoring other irrelevant features. However, such selectivity has its drawbacks. In information-rich environments, such as driving a car or landing an aircraft, vision can fail to cope, and accidents can result. Accordingly, much recent research in psychophysics and ergonomics has examined how display characteristics affect our ability to process multiple features of the visual environment simultaneously. The majority of these experiments has found that performance can be optimized by combining several features into one visual 'object'. In contrast, several recent studies from my own laboratory have found the opposite pattern, indicating that information sources can often be more efficiently processed when they belong to separate objects. Indeed, these data suggest that the number of objects has no general effect on our perceptual performance. Instead, I argue for a two-pathway approach to understanding human visual capacities, and suggest that this approach may have important implications for a diverse range of display technologies, including cockpit displays.