In many everyday tasks, close coordination between eye movements and cognitive processes is essential for smooth performance. Because natural environments often confront us with multiple sources of information that could potentially control or guide our behavior, a central aspect of coherent perceptual-motor processes must entail the ability to select and respond to momentarily relevant objects and the ability to ignore irrelevant objects. Determining how the brain accomplishes this remains a core issue in cognitive psychology. Empirical investigations involving negative priming paradigms provide evidence for the existence of both distractor inhibition and episodic retrieval mechanisms in selective attention. Moreover, the coexistence of these processes may help to explain the apparently effortless performance of humans in situations that require a series of selective actions. The present eye-tracking experiments are designed to help us understand more fully the nature of the mechanisms underlying the selection of static objects in the environment, and the control of spatially directed actions. Additional experiments using familiar and unfamiliar objects, as well as possible and impossible three-dimensional shapes, are underway in order to extend the present investigation. These experiments are designed to produce vital supplementary information regarding the nature of the memory traces laid down by familiar and novel unattended stimuli, and how long their respective implicit memories last. The better we understand these processes in normals, the more well equipped we will be in applying this knowledge to LSES's ongoing investigations of schizophrenia and normal aging.
