牛谷 智一

In our target article published in the latest special issue of the Japanese Journal of Animal Psychology, we proposed a new framework of species comparison for studies of animal psychology in which the generalist and evolutionist approaches were incorporated. The 13 open peer commentaries to the target article, the pros and cons, provided valuable criticisms on our proposal. Although generalists were skeptical of scientific validity of the evolutionist approach due to its difficulty of experimental examination, we think that species comparison allows us to test evolutionist hypotheses with ...

The purpose of this article was to address issues on what the role of species comparison is for the studies of animal psychology. Whereas some people think that the comparison has a critical role in their approaches, others do not. We classify these two groups of people as evolutionists and generalists, respectively. In the evolutionary approach, different species are compared to examine correlations between specific selective pressures (such as caching food) and cognitive abilities (such as spatial learning) in animals. In contrast, different species of animals are compared to examine univ...

We investigated object-based attention in chimpanzees with an attention shift task. The chimpanzees were rewarded by touching a target (a red disk) which appeared after a brief presentation of a cue (a yeHow square). We hypothesized that if object-based attention does work, the reaction time (RT) would be shorter when the target appeared in the cued rectangle than in the other rectangle. We could not observe any evidence of such a within-object benefit in Experiment 1, in which two rectangles were arranged in parallel. In Experiment 2, the rectangles were arranged horizontally in a line, to reduce variation in the distance from the start key to each target location. The RT pattern of the chimpanzees in Experiment 2 suggested an object-based attention in them.