Describes a series of experiments showing that in normal subjects (a) iconic storage occurs primarily in the retina in the photoreceptors and (b) under conditions of dark pre- and postexposure fields, the icon is mainly a rod phenomenon. Draws conclusions based on these experiments, discusses previous work done by others, and attempts to reconcile…

Three experiments are reported that were designed to delineate the properties of the stimulus encoding stage in reaction time tasks of varying stimulus-response compatibility. (Editor)

Discusses two propositions about the preliminary stages of acoustic analysis and encoding in the absence of focal attention. (Editor/RK)

In four different experiments, brief illumination of a localized visual stimulus was followed by grain presentation unless the pigeon approached the light. Results indicate that although response-reinforcer relations do play a role, stimulus-reinforcer contingencies are the dominant factor in establishing and maintaining approaches to the…