The long-term objective of the proposed work is to provide the first comprehensive view of how multisensory function changes across lifespan. Emerging literature suggests a surprisingly long development process leading up to the mature multisensory state, and intriguingly that multisensory function in later life may compensate to some degree for age-related loss of acuity within the individual senses. In addition to being the first project to detail these changes across lifespan, the work will provide important windows into individual variability in multisensory function, and how certain domains of multisensory function map onto other domains (e.g., spatial vs. temporal function). Finally, the work seeks to detail relationships between multisensory abilities and higher cognitive processes, given that cognition is grounded in both the integrity of the information contained within the incoming sensory streams and the integration between these streams. The experimental approach will employ a sophisticated battery of tasks to assess and relate multisensory and cognitive function. The proposed studies are oriented around two specific aims. The first is to characterize multisensory function in individuals ranging in age from 5 to 85. The second is to relate performance on our battery of multisensory tasks to performance on well-established cognitive tasks that index domains such as attention and working memory. Collectively these studies are predicated on the framework that multisensory function will change in systematic ways across lifespan, and that these changes will have important relationships to cognition. The significance of work lay in its potential to establish these relationships, which will have important implications for furtherig our understanding of the maturation and aging of perceptual and cognitive representations - issues of powerful