Investigation of Object-Based Attention in Pigeons (Columba livia) and Hill Mynas (Gracula religiosa) Using a Spatial Cueing Task

In previous research, pigeons and hill mynas that performed differently on an object permanence task were presumed to attend to objects in different ways (Plowright, Reid, & Kilian, 1998). In the current study, we conducted 4 experiments to investigate if the attention of hill mynas and pigeons is object-based and if there are species differences in their visual-attentional processes. In Experiment 1, pigeons were tested in a spatial cueing task requiring them to respond sequentially to a cue and a target that appeared at 1 of the 4 ends of two rectangles. Both when the response to a fixation stimulus was required before target presentation (Experiment 1A) and when such a response was not required (Experiment 1B), there were no significant differences in reaction times to the targets appearing at cued and noncued rectangles; these results provided no evidence of object-based attention in pigeons. In Experiment 2, for 2 of the 3 hill mynas tested in a procedure similar to that for the pigeons in Experiment 1B, reaction times were shorter to the target appearing on the cued rectangle than to the target appearing on noncued rectangle, suggesting the operation of object-based attention, as in humans. In Experiment 3, we tested naive pigeons by means of the procedure used for hill mynas in Experiment 2. However, again pigeons showed no evidence of object-based attention, suggesting a species difference in attentional processes. The generality of the current results and evolution of the possible species differences were discussed.