Owners' direct gazes increase dogs' attention-getting behaviors.

This study examined whether dogs gain information about human's attention via their gazes and whether they change their attention-getting behaviors (i.e., whining and whimpering, looking at their owners' faces, pawing, and approaching their owners) in response to their owners' direct gazes.

Efficient visual search for multiple targets among categorical distractors: effects of distractor-distractor similarity across trials.

We trained one group of pigeons to search for members of an artificial category among category-unspecified nonmembers. For another group of pigeons, the roles of the targets and of the distractors were reversed. Experiment 1 found that the latter group showed surprisingly efficient search for multiple nonmembers.

Pigeons show efficient visual search by category: effects of typicality and practice.

Three experiments investigated category search in pigeons, using an artificial category created by morphing of human faces. Four pigeons were trained to search for category members among nonmembers, with each target item consisting of an item-specific component and a common component diagnostic of the category. Experiment 1 found that search was more efficient with homogeneous than heterogeneous distractors.

The learning of basic-level categories by pigeons: the prototype effect, attention, and effects of categorization.

Pigeons were trained to classify composite faces of two categories created by mimicking the structure of basic-level categories, with each face consisting of an item-specific component and a common component diagnostic for its category. Classification accuracy increased as the proportion of common components increased, regardless of familiar and novel item-specific components, with the best discrimination occurring at untrained original faces used as the common components. A no-categorization control condition suggested that categorization gives rise to equivalence for item-specific components and distinctiveness for degrees of prototypicality.