Visual functioning is related to independence in later adulthood. One of the most ubiquitous findings in research on cognitive aging is that older adults take longer to perform visually based tasks. The nature of the observed cognitive slowing, specifically whether it is general vs. task- or process-specific, is the focus of much current research. This research uses a recent queuing-theory based mathematical model which was developed to investigate task-and process-related contributions to age-related differences in visual information processing. In order to progress towards the goal of making model-based design recommendations, more research is required to understand the effect of other factors which are present in real-world tasks, including: (1) consistent versus varied mapping of stimuli to responses, (2) the relative ease or difficulty in distinguishing between relevant and irrelevant information (target-distractor similarity), (3) having to process other information types than simple alphanumeric (e.g., graphical symbols and words,) (4) gaining an understanding of the individual differences in processing structures and the basic cognitive abilities to which they are related. A series of laboratory-based experiments using the multiple-frame visual search paradigm is proposed to investigate age-related differences in the effects of these factors. The Ellis and Chandra mathematical model of information processing will be fit to these data. The long-term objective of the research program is to contribute quantitative design recommendations based on the mathematical modeling approach. It is only with a broad base of information on performance that design recommendations can ultimately be made. The modeling approach proposed in this research will ultimately be useful in making life-span oriented, human factors design recommendations for tasks, equipment, and products.
