Papers in the Biological Sciences


Date of this Version



Published in Journal of Experimental Psychology: Animal Behavior Processes 9:3 (1983), pp. 292–306. Copyright © 1983 by the American Psychological Association, Inc. Used by permission. “This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.”


During visual search for samples of varying proportions of familiar, natural food grains displayed against a complex gravel background, pigeons exhibited “matching selection,” a tendency to overselect the more common grain. The matching selection effect was decreased at low levels of stimulus/background contrast and reversed when the grains were highly conspicuous. The results were consistent with the hypothesis that stimulus detectability should be enhanced by recent experience with a particular grain type, but they showed no convincing indications of a corresponding effect on the response criterion. An explanatory model, termed the attention threshold hypothesis, argues that the mean latency of discovery can be minimized by selectively attending to one stimulus type at a time and switching to a more generally receptive state when the rate of discovery falls below a threshold value. The model appears to account for the fact that the response rate was highest toward samples containing a single grain type and decreased as the relative proportions approached equality. Additional consequences of the adoption of this theoretical perspective were explored in some detail. Among other results, the evidence suggests that the switching threshold might be chosen so as to optimize the rate of food discovery.