Logo image
Pigeons spontaneously form three-dimensional shape categories
Journal article   Peer reviewed

Pigeons spontaneously form three-dimensional shape categories

Jessie J Peissig, Michael E Young, Edward A Wasserman and Irving Biederman
Behavioural processes, Vol.158, pp.70-76
01/2019
DOI: 10.1016/j.beproc.2018.11.003
PMID: 30439476
url
https://pmc.ncbi.nlm.nih.gov/articles/PMC10631373/pdf/nihms-1813809.pdfView
Open Access

Abstract

•Pigeons easily learn to associate views of the same object to one response.•Pigeons find it difficult to learn to associate views of the same object to different responses.•Pigeons attended to object-specific features rather than just stimulus-specific information.•Pigeons spontaneously categorize together different orientations in depth of the same 3D object. We explored the pigeon’s representation of the shape of simple three-dimensional objects (geons) rotated in depth (four views each of four geons). Pigeons assigned to the Categorization group had to respond differentially to images of four different geons—termed arch, barrel, brick, and wedge—based on their 3D shape, regardless of the orientation of the object. Pigeons assigned to the Pseudocategorization group had to respond differentially to the same objects based on groupings that did not correspond to object identity, which required the learning of local orientation-dependent features (e.g., a concave curve on top, or the position of an illumination hotspot). The Categorization group, which could employ object-identity representations, quickly achieved highly accurate responding. The Pseudocategorization group, however, failed to achieve reliable above-chance responding. In addition, the reaction times for the Categorization group were significantly shorter than for the Pseudocategorization group. These results indicate that pigeons show a strong, spontaneous tendency to categorize the shapes of different orientations in depth of the same 3D object as similar, if not equivalent; they do so despite the vast differences in image characteristics caused by the variations in orientations, even when such categorization is contrary to the reinforcement contingencies.
Visual Perception Pseudocategory Object recognition Categorization Pigeons

Details

Metrics

Logo image