The ability to discriminate between and to selectively attend to different stimulus events are fundamental properties of adaptive behavior. The mechanisms underlying the important processes of attention and discrimination learning are discovered by studying how animals respond to different stimuli that signal other, biologically important events. Although external events have typically been used in research in this area, experimental psychologists have recently begun to study how internal stimuli or "codes" are also involved in these processes. In this project, Dr. Urcuioli will examine the role of two types of internal stimuli in attention and discrimination: the feedback arising from an animal's own behavior (response codes), and the expectancy of future rewarding events (expectancy codes). The general procedure for most of the experiments will be to present animals with one of two possible visual stimuli, followed shortly thereafter by two different choice alternatives, on each trial. One alternative will be designated "correct" following one initial stimulus, and the other alternative will be correct following the remaining initial stimulus. Response and expectancy codes will be generated by requiring the animals either to respond differently to the two initial stimuli, or by correlating these visual events with different outcomes following each choice alternative. Later, the animals will be tested to determine whether or not their choices are being cued by the response or expectancy codes and, if so, how their attention to these internal events affects their attention to the redundant visual stimuli present at the beginning of each trial. This research project is important to our understanding of the internal, cognitive processes of non-human animals, and will provide data relevant to the question of whether or not the mechanisms of selective attention and discrimination are similar for internal as well as external stimulus events.
