Illusory contour perception in domestic dogs
One way to better understand how animals visually perceive their environment is to assess the way in which visual information is interpreted and adapted based on preconceptions. Domestic dogs represent a unique species in which to evaluate visual perception as recent findings suggest they may differ from humans and other animal species in terms of their susceptibility to geometric visual illusions. Dogs have demonstrated human-like, reversed, and null susceptibility depending on the type of illusion. To further evaluate how dogs perceive their environment, it is necessary to perform additional assessments of visual perception. One such assessment is the perceptual filling-in of figures, which may be invoked when presented with illusory contours. Six dogs were assessed on their perception of the Ehrenstein illusory contour illusion in a two-choice size-discrimination task. Dogs, as a group, demonstrated equivocal perception of illusory contours. Some individual dogs, however, demonstrated human-like perception of the subjective contours, providing preliminary evidence that this species is capable of perceiving illusory contour illusions, thereby improving the current understanding of canine visual perception capabilities. Additional assessments using alternative illusory contour illusions are needed to clarify these results and identify features that underpin the individual differences observed.
KeywordsDog Ehrenstein Illusion Perception Illusory contour
We are grateful to Lynna Feng, Nicholas Rutter, and Jessica Woodhead for their help in previous training processes. We also thank Ron Wheeler for his assistance in the construction and design of our apparatus, and Davis Vorva for his expertise in program design. This study was carried out with the support of a La Trobe University Postgraduate Research Scholarship and a La Trobe University Full Fee Research Scholarship.
Open practices statement
The data and programs for this experiment are available upon request.
- Bensky, M. K., Gosling, S. D., & Sinn, D. L. (2013). The world from a dog’s point of view: A review and synthesis of dog cognition research. Advances in the Study of Behaviour, 45, 209-406. https://doi.org/10.1016/B978-0-12-407186-5.00005-7 CrossRefGoogle Scholar
- Byosiere, S.-E., Feng, L. C., Chouinard, P. A., Howell, T. J., & Bennett, P. C. (2017). Relational concept learning in domestic dogs: Performance on a two-choice size discrimination task generalises to novel stimuli. Behavioural Processes https://doi.org/10.1016/j.beproc.2017.10.009 CrossRefGoogle Scholar
- Byosiere, S.-E., Feng, L. C., Rutter, N. J., Woodhead, J. K., Chouinard, P. A., Howell, T. J., & Bennett, P. C. (2017). Do dogs see the Ponzo illusion? Animal Behavior and Cognition. 10.26451/abc/04.04.01.2017Google Scholar
- Byosiere, S.-E., Feng, L. C., Woodhead, J. K., Rutter, N. J., Chouinard, P. A., Howell, T. J., & Bennett, P. C. (2016). Visual perception in domestic dogs: susceptibility to the Ebbinghaus–Titchener and Delboeuf illusions. Animal Cognition, 1–14. https://doi.org/10.1007/s10071-016-1067-1 CrossRefGoogle Scholar
- Chouinard, P. A., Noulty, W. A., Sperandio, I., & Landry, O. (2013). Global processing during the Müller-Lyer illusion is distinctively affected by the degree of autistic traits in the typical population. Experimental Brain Research, 230(2), 219-231. https://doi.org/10.1007/s00221-013-3646-6 CrossRefPubMedGoogle Scholar
- Chouinard, P. A., Unwin, K. L., Landry, O., & Sperandio, I. (2016). Susceptibility to optical illusions varies as a function of the autism-spectrum quotient but not in ways predicted by local–global biases. Journal of Autism and Developmental Disorders, 46(6), 2224-2239. https://doi.org/10.1007/s10803-016-2753-1 CrossRefPubMedGoogle Scholar
- Kandel, E., & Schwartz, J. (2000). Jessell. TM. Principles of Neural Science. In: New York, NY: McGraw Hill.Google Scholar
- Kanizsa, G. (1974). Contours without gradients or cognitive contours? Italian Journal of Psychology, 1(1), 93-112.Google Scholar
- Schumann, F. (1900). Beiträge zur Analyse der Gesichtswahrnehmungen. Erste Abhandlung. Einige Beobachtungen über die Zusammenfassung von Gesichtseindruecken zu Einheiten. Zeitschrift für Psychologie und Physiologie der Sinnesorgan (23), 1–32.Google Scholar
- Wetzels, R., Matzke, D., Lee, M. D., Rouder, J. N., Iverson, G. J., & Wagenmakers, E.-J. (2011). Statistical evidence in experimental psychology:An empirical comparison using 855 t tests. Perspectives on Psychological Science, 6(3), 291-298. https://doi.org/10.1177/1745691611406923 CrossRefPubMedGoogle Scholar