The influence of size and pattern cues in a visual discrimination task on a touchscreen computer in the domestic dog.

Abstract

Visual discrimination is a crucial skill for many species to enable them to react in an appropriate way to different stimuli. It is the ability to recognize differences in visual images. Global features and more detailed cues like size, shape, colour, pattern, brightness can be used to provide the information they need. The question whether dogs share similar cognitive abilities to humans plays an important role in recent research. It may give us insight in evolutionary developments that led to our human way of thinking. Knowledge of which visual cues are important to dogs would significantly increase our understanding about canine visual perception. Previous research indicates that size and pattern are more important than shape in a purely visual discrimination task. Another remaining part is to investigate whether dogs rather use size or pattern preferentially in a visual two-choice task. In this study, four dogs were trained to discriminate between two positive and two negative size and pattern combinations using a touchscreen computer. After training, tests were introduced in which positive and negative size and pattern cues were mismatched, to investigate which cue exerted more influence over their choice. They were also presented with tests to determine if they could still recognize the image when size and pattern cues were presented individually. Two dogs used pattern in preference to size in the cue mismatch test and all four dogs were able to solve the discrimination with only pattern information, while only one was able to discriminate using only size cues. These results suggest that pattern may be more salient than size in a purely visual discrimination task but more research and a larger sample size is needed to drawn any strong conclusions.