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The combination of highly controlled experimental testing and the voluntary participation of unrestrained animals has many advantages over traditional, laboratory-based learning environments in terms of animal welfare, learning speed, and resource economy. Such automatic learning environments have recently been developed for primates (Fagot & Bonté, 2010; Fagot & Paleressompoulle, 2009;) but, so far, has not been achieved with highly mobile creatures such as birds. Here, we present a novel testing environment for pigeons. Living together in small groups in outside aviaries, they can freely choose to participate in learning experiments by entering and leaving the automatic learning box at any time. At the single-access entry, they are individualized using radio frequency identification technology and then trained or tested in a stress-free and self-terminating manner. The voluntary nature of their participation according to their individual biorhythm guarantees high motivation levels and good learning and test performance. Around-the-clock access allows for massed-trials training, which in baboons has been proven to have facilitative effects on discrimination learning. The performance of 2 pigeons confirmed the advantages of the automatic learning device for birds box. The latter is the result of a development process of several years that required us to deal with and overcome a number of technical challenges: (1) mechanically controlled access to the box, (2) identification of the birds, (3) the release of a bird and, at the same time, prevention of others from entering the box, and (4) reliable functioning of the device despite long operation times and exposure to high dust loads and low temperatures.

Attentional capture is usually stronger for task-relevant than irrelevant stimuli, whereas irrelevant stimuli can trigger equal or even stronger amounts of inhibition than relevant stimuli. Capture and inhibition, however, are typically assessed in separate trials, leaving it open whether or not inhibition of irrelevant stimuli is a consequence of preceding attentional capture by the same stimuli or whether inhibition is the only response to these stimuli. Here, we tested the relationship between capture and inhibition in a setup allowing for estimates of the capture and inhibition based on the very same trials. We recorded saccadic inhibition after relevant and irrelevant stimuli. At the same time, we recorded the N2pc, an event-related potential, reflecting initial capture of attention. We found attentional capture not only for, relevant but importantly also for irrelevant stimuli, although the N2pc was stronger for relevant than irrelevant stimuli. In addition, inhibition of saccades was the same for relevant and irrelevant stimuli. We conclude with a discussion of the mechanisms that are responsible for these effects.

No abstract

Presenting consistent objects in scenes facilitates object recognition as compared to inconsistent objects. Yet the mechanisms by which scenes influence object recognition are still not understood. According to one theory, consistent scenes facilitate visual search for objects at expected places. Here, we investigated two predictions following from this theory: If visual search is responsible for consistency effects, consistency effects could be weaker (1) with better-primed than less-primed object locations, and (2) with less-primed than better-primed scenes. In Experiments 1 and 2, locations of objects were varied within a scene to a different degree (one, two, or four possible locations). In addition, object-scene consistency was studied as a function of progressive numbers of repetitions of the backgrounds. Because repeating locations and backgrounds could facilitate visual search for objects, these repetitions might alter the object-scene consistency effect by lowering of location uncertainty. Although we find evidence for a significant consistency effect, we find no clear support for impacts of scene priming or location priming on the size of the consistency effect. Additionally, we find evidence that the consistency effect is dependent on the eccentricity of the target objects. These results point to only small influences of priming to object-scene consistency effects but all-in-all the findings can be reconciled with a visual-search explanation of the consistency effect.