patricia M. Blough - US grants

This special award will give Ph.D. student Dolores V. Bradley additional flexibility in pursuing her graduate studies and research initiation in experimental psychology. This award will strengthen minority participation in research in this area.

Humans and other higher animals must select relevant information from the huge amount of data provided by the senses at every moment. The Bloughs' research project seeks to clarify how this selective process, "attention," works in the case of visual information. They chose the pigeon as their subject because it has extremely good vision, unlike most small and inexpensive animals studied by biologists and psychologists. The pigeon is an excellent animal model in which to explore how the brain is able to interpret the visual world. Although most of our understanding of perception and attention comes from studying humans, that understanding is limited in a number of ways. Biological processes have always been understood most deeply by comparing and contrasting them in different species. Learning and motivation play a major role in attention, and researchers can vary and control these factors in animal subjects. Attention may be simpler and easier to understand in pigeons than in humans; humans use complex strategies and thought processes that may obscure relatively simple mechanisms. Above all, by using an animal subject, the Bloughs hope eventually to contribute to the complete understanding of mental processes that will come only from relating behavioral results directly to evidence from physiological experiments in the same species. This understanding of neural processes is a major goal of science and a necessary background for the treatment of behavioral and mental disorders.

This research concerns ways in which experience fine-tunes perception. Examples are the practiced worker's ability to detect subtle flaws in a product, or a person's ability to identify quickly a familiar face in a crowd. The research will follow two lines. The first concerns a relatively short-term effect called priming, seen when advance information about a stimulus leads to its more efficient detection. Experiments will determine the precise nature of such perceptual changes and will address the manner in which primed expectancies are learned. A second line of research concerns more permanent perceptual learning. Experiments will investigate what changes in perception occur with practice, how changes in one task may affect performance on others, and the possibility that perceptual learning involves costs as well as benefits. In order to study such learning it is necessary to control the subject's visual experience. The Bloughs' experiments use pigeons, whose excellent vision is well understood; pigeons and primates, including humans, process visual information in many similar ways. This work is unique in its focus on relations between perception and learning. The use of relatively simple stimuli combined with the tools of psychophysical anslysis will permit the Bloughs to distinguish among stimulus-based variables and several classes of experiential factors as determiners of what is seen.