Although the visual world consists of multiple sources of information, there are fundamental limits on the ability of humans to process multiple stimuli simultaneously. Thus, a selection mechanism is needed that determines which sources of information are processed or "attended" at any given point in time. This selection mechanism is subject to two competing constraints. On the one hand, efficiency dictates that only those events relevant to current behavioral goals should be attended. On the other hand, adaptability suggests that salient stimuli or events that may be relevant to the establishment of new goals should also be attended. The goal of this research is to explorea model of how the selection mechanism manages to satisfy both efficiency and adaptability to produce successful interaction with the environment. The basic premise of the model is that salient, potentially important stimulihave the ability to automatically "capture" or drawn attention to themselves, but that such attentional capture is ultimately contingent on whether theobserver is set to respond to that property. One series of studies will critically test this "contingent capture" model against other existing theoretical accounts. The remaining studies will explore issues such as the functional stimulus classes for which selection mechanism can be set, and the functional mechanisms by which these attentional control settings are instantiated. In addition to elucidating the nature of the selective attention mechanism, this research may also have important applied implications for the development of display systems that maximize the efficiency of information transfer between display and operator, as well as for the diagnosis and treatment of the "distractability" associated with many mental disorders. Finally, it may serve as a guiding framework for exploring the underlying brain mechanisms associated with attentional control.
