With few exceptions, architectural approaches to modeling\ncognition have historically emphasized what happens in the\nmind following the transduction of environmental signals into\npercepts. To our knowledge, none of these architectures\nimplements a sophisticated, general theory of human attention.\nIn this paper we summarize progress to date on a new cognitive\narchitecture called ARCADIA that gives a central role to\nattention in both perception and cognition. First, we give an\noverview of the architecture, comparing it to other approaches\nwhen appropriate. Second, we present a model of incremental\nobject construction and property binding in ARCADIA using\nthe well known change blindness phenomena to illustrate the\ntime course of object perception and its dependence on attention.\nFinally, we discuss near-term challenges and future plans