Location as a feature in pigeons’ recognition of visual objects

Abstract

A number of different phenomena in pigeon visual cognition suggest that pigeons do not immediately recognize two identical objects in different locations as being “the same”. To examine this question directly, pigeons were trained in an absolute go/no-go discrimination between arbitrary selections from sets of 16 images of paintings by Claude Monet. Of the eight positive stimuli, four always appeared in the same location, while the other four appeared equally often in each of two locations; the same was true of the negative stimuli. There was a consistent tendency for stimuli that appeared in a single position to be better discriminated than those that appeared in two positions, although by the end of training, this effect was confined to negative stimuli. This result suggests that, for a pigeon, an image’s location is one of the bundle of features that define it, and that pigeons need to learn to abstract from that feature rather than doing so automatically.