A theory of perception and attention that emphasizes the relational nature o { perceptual invariants is developed within the context of auditory pattern research. The theory is divided into two parts. The first part, addresses world pattern structure; the second describes interaction of organisms with pattern structure. Tn the former, world patterns arc subjectively represented as nested relations within a multidimensional space defined by pilch, loudncss, and time. But dependency of these defining dimensions means that a pattern's lime scale determines the serial integrity of its pitch/loudness structure. Second, the theory proposes a time scale for living things that is manifest in graded perceptual rhythms. These rhythms can be synchronized to corresponding nested time zones within world pattern structure. Related assumptions about the deployment of physical energy across time zones and cognitive locations of perceptual rhythms lead to a simple, but general, attentional theory. Theoretical support, found in research with tone patterns, speech, and sequences of noise is died in a final section. Beyond this focal research, the theory offers a general framework for understanding diverse phenomena thai range from speech perception and aphasia to sleep, growth, and time eslimation. The ideas presented in this paper are the foundation for a new way to understand human perception and memory. They are developed within the context of research with auditory patterns, but the general approach has implications for man} ' other areas of inquiry. Nevertheless, their most immediate relevance is to research and theory in speech and auditory pattern perception. The specific problems which give rise to this theory arc briefly outlined in the next section. This article was prepared with the support of National Science Foundation Grant UMS74-21492.

Iconic memory has often been likened to a sensory store whose contents drain away rapidly as soon as the inducing stimulus is turned off. Instances of short-lived visible persistence have been explained in terms of the decaying contents of iconic store. A fundamental requirement of this storage model is that strength of persistence should be a decreasing function of time elapsed since the cessation—not since the onset—of the inducing stimulation. That is, strength of visible persistence may be directly related—but not inversely related—to the duration of the inducing stimulus. Two complementary paradigms were utilized in the present studies. In the first paradigm performance was facilitated by visible persistence in that the task required the bridging of a temporal gap between two successive displays. In the second paradigm (forward visual masking by pattern), performance was impaired by lingering visible persistence of the temporally leading mask. Both paradigms yielded evidence of an inverse relationship between duration of inducing stimulus and duration of visible persistence.