Part-Based and Configural Processing of Owner's Face in Dogs

Abstract

Dogs exhibit characteristic looking patterns when looking at human faces but little is known about what the underlying cognitive mechanisms are and how much these are influenced by individual experience. In Experiment 1, seven dogs were trained in a simultaneous discrimination procedure to assess whether they could discriminate a) the owner's face parts (eyes, nose or mouth) presented in isolation and b) whole faces where the same parts were covered. Dogs discriminated all the three parts of the owner's face presented in isolation, but needed fewer sessions to reach the learning criterion for the eyes than for both nose and mouth. Moreover, covering the eyes region significantly disrupted face discriminability compared to the whole face condition while such difference was not found when the nose or mouth was hidden. In Experiment 2, dogs were presented with manipulated images of the owner's face (inverted, blurred, scrambled, grey-scale) to test the relative contribution of part-based and configural processing in the discrimination of human faces. Furthermore, by comparing the dogs enrolled in the previous experiment and seven ‘naïve’ dogs we examined if the relative contribution of part-based and configural processing was affected by dogs' experience with the face stimuli. Naïve dogs discriminated the owner only when configural information was provided, whereas expert dogs could discriminate the owner also when part-based processing was necessary. The present study provides the first evidence that dogs can discriminate isolated internal features of a human face and corroborate previous reports of salience of the eyes region for human face processing. Although the reliance on part-perception may be increased by specific experience, our findings suggest that human face discrimination by dogs relies mainly on configural rather than on part-based elaboration.

The perception of human faces by dogs: Perceptual and cognitive adaptations

“…The latter ability was tested in our lab using the touch-screen technology. We found that dogs can discriminate human faces by using the internal facial features (eyes, nose, mouth and their configuration) only (Pitteri et al, 2014). Other recent data from our lab suggest that dogs share with human infants a pattern of visual preferences for features consistent with the human eye (local contrast polarity) that may represent a foundational perceptual tool for life in human society.…”

Perception of dynamic facial expressions of emotion between dogs and humans

“…It is unlikely that dogs simply are working hard to attend to all the facial elements to look for information, because, if this was the case, the areas of the face attended to should reflect the information available from these regions in any given state. Instead, the configural processing of familiar faces in dogs (Pitteri et al 2014) is here extended to facial expressions. Configural processing (sensu Bruce and Young 2012) is early and well developed in humans (de Heering et al 2007), and found in varied taxa, including chimpanzees (Parr et al 2008), sheep (Kendrick et al 1996), pandas (Li et al 2017), and even bees (Dyer 2005).…”

Orienting asymmetries and physiological reactivity in dogs’ response to human emotional faces

“…They are able to discriminate familiar human faces using the global visual information both of the faces and the head (Huber, Racca, Scaf, Virányi, & Range, 2013), scanning all the facial features systematically (e.g. eyes, nose and mouth; Somppi et al, 2016) and relying on configural elaboration (Pitteri, Mongillo, Carnier, Marinelli, & Huber, 2014). Moreover, dogs, as well as humans, focus their attention mainly in the eye region, showing faces identification impairments when it is masked (Pitteri et al, 2014;Somppi et al, 2016).…”

“…eyes, nose and mouth; Somppi et al, 2016) and relying on configural elaboration (Pitteri, Mongillo, Carnier, Marinelli, & Huber, 2014). Moreover, dogs, as well as humans, focus their attention mainly in the eye region, showing faces identification impairments when it is masked (Pitteri et al, 2014;Somppi et al, 2016). Interestingly, their gazing pattern of faces informative regions varies according to the emotion expressed.…”