Object recognition in pigeons: The effects of spatial frequencies

Abstract

We explored the effects of spatial frequency filtering on the visual recognition performance of pigeons. By comparing the effects of spatial frequency filtering across two very different species, we sought to determine the species-generality of prior human studies. In our experiments, pigeons were trained with either fully-shaded representations of three-dimensional objects or with line drawings of the same objects. Those pigeons that were trained with shaded images exhibited more control by the low spatial frequencies of the visual stimuli, whereas those pigeons that were trained with line drawings exhibited more control by the high spatial frequencies. This result suggests that pigeons may preferentially use low spatial frequencies when trained with more realistic objects, but they will use high spatial frequencies when required to do so. Continued research using pigeons and other species will determine what role spatial frequencies play in general recognition processes.