SHARED ATTENTION IN PIGEONS - RETRIEVAL FAILURE DOES NOT ACCOUNT FOR THE ELEMENT SUPERIORITY EFFECT

Matching-to-sample accuracy by pigeons is generally poorer on compound -sample trials (when only one of the elements is tested) than on eleme nt sample trials. This phenomenon, known as the element superiority ef fect (ESE), has been attributed to the pigeon's limited capacity to pr ocess the sample, Recently, a retrieval failure account has been sugge sted (Lamb, 1991): it takes the pigeon longer to retrieve the relevant element when there are two elements rather than one in memory. In the present research. little support for a retrieval failure account of t he ESE was found. Neither extending the period of comparison respondin g by using a successive matching task (Experiment 1), nor examining no rmal variations in the magnitude of the pigeons' comparison choice lat ency in a simultaneous matching task (Experiment 2), nor forcing the p igeon to delay its choice of comparisons (Experiment 3), significantly affected the magnitude of the ESE. The present results are consistent with an attentional (limited processing capacity) account of the ESE. (C) 1997 Academic Press.