Domesticated dogs’ (Canis familiaris) use of the solidity principle

Shannon M. A. Kundey, Chelsea Taglang, Ayelet Baruch, and Rebecca German, Department of Psychology, Hood College; Andres De Los Reyes, Comprehensive Assessment and Intervention Program, Department of Psychology, University of Maryland at College Park. We would like to thank Jessica Arbuthnot, Rebecca Allen, Ariel Coshun, Erica Royer, Sherry McClurkin, Sabrina Molina, and Robin Reutten for their assistance in data collection and participant recruitment for this study.Organisms must often make predictions about the trajectories of moving objects. However, often these objects become hidden. To later locate such objects, the organism must maintain a representation of the object in memory and generate an expectation about where it will later appear. We explored adult dogs’ knowledge and use of the solidity principle (that one solid object cannot pass through another solid object) by evaluating search behavior. Subjects watched as a treat rolled down an inclined tube into a box. The box either did or did not contain a solid wall dividing it in half. To find the treat, subjects had to modify their search behavior based on the presence or absence of the wall, which either did or did not block the treat’s trajectory. Dogs correctly searched the near location when the barrier was present and the far location when the barrier was absent. They displayed this behavior from the first trial, as well as performed correctly when trial types were intermingled. These results suggest that dogs direct their searches in accordance with the solidity principle

Domesticated dogs (Canis familiaris) react to what others can and cannot hear

Corresponding author at: Hood College, Department of Psychology, 401 Rosemont Avenue, Room ROS 27, Frederick, MD 21701, USA. Tel.: +1 301 696 3877. E-mail address: [email protected] (S.M.A. Kundey).Recent research suggests some nonhuman primates (e.g., chimpanzees, rhesus macaques) consider what others hear when acting in competitive situations. We explored whether dogs living in private homes or sourced from an animal shelter would show this same predilection. Following an inhibition task where dogs (Canis familiaris) were commanded not to take a treat left on a plate by a human, we presented subjects with the opportunity to take food from one of two containers. These containers were located within the proximity of a human gatekeeper who was either looking straight ahead or not looking at the time of choice. One container was silent when food was inserted or removed while the other was noisy. Among pet dogs (20 total; 10 in each condition) randomly assigned to the Looking or Not Looking condition, four subjects approached the silent container in the Looking condition (binomial test: P = 0.8) while 10 approached the silent container in the Not Looking condition (binomial test: P = 0.004). We compared pet dogs’ pattern of performance between conditions using a chi-square test for independence, which indicated that dogs significantly preferred the silent container only in the Not Looking condition (Chi-square [1] = 8.8, P = 0.003). This outcome suggests dogs preferentially attempted to retrieve food silently only when silence was germane to obtaining food unobserved by the human gatekeeper. Interestingly, dogs sourced from a local animal shelter evidenced similar outcomes. Among shelter dogs (20 total; 10 in each condition) randomly assigned to the Looking or Not Looking condition, four subjects approached the silent container in the Looking condition (binomial test: P = 0.8) while nine approached the silent container in the Not Looking condition (binomial test: P = 0.02).We compared shelter dogs’ pattern of performance between conditions using a chi-square test for independence, which indicated that dogs significantly preferred the silent container only in the Not Looking condition (Chi-square [1] = 5.5, P = 0.02). This result suggests shelter dogs, like pet dogs, preferentially tried to retrieve food silently only if silence was relevant to obtaining food unobserved by a human gatekeeper. This result conflicts with other recent data suggesting that shelter dogs perform more poorly than pet dogs in tasks involving human social cues

Domesticated Dogs’ (Canis familiaris) Response to Dishonest Human Points

We would like to thank Sherry McClurkin, Robin Reutten, and Chelsea Taglang for their assistance in data collection and participant recruitment for this study. Correspondence concerning this article should be addressed to Shannon M.A. Kundey at Hood College, Department of Psychology, 401 Rosemont Avenue, Room ROS 27, Frederick, MD 21701, U.S.A. ([email protected]).Pointing is a conventional communicative gesture used by humans to direct others’ attention to an environmental feature. Several researchers have argued that pointing becomes so ingrained for humans from a young age that children often have difficulty interpreting the gesture in a novel way. Recent research suggests domestic dogs are also sensitive to human gestures (including points) and proficient in recognizing and acting on humans’ visual attention. We explored the role of pointing in dogs’ choice behavior and whether dogs, like human children, have difficulty interpreting the gesture novelly. In Experiment 1, we explored whether dogs would differentially follow a static human point when it was administered by a familiar or unfamiliar individual and that individual indicated or failed to indicate the correct location of a food reward. The results indicated dogs chose the container specified by the demonstrators’ point in the honest and dishonest condition. Demonstrator familiarity did not alter performance. In Experiment 2, we compared dogs’ propensity to follow a static point versus other cues (momentary point, standing location) when the cue never indicated the correct location of a food reward, which was either visible or hidden during choice. The results suggested dogs did not inhibit their approach to a location indicated by a deceptive static point even when the location of a reward was visibly available during choice. However, dogs used a deceptive momentary point or standing location to locate food in both visible and hidden trials. In Experiment 3, we explored if dogs could overcome their tendency to follow a deceptive static point. These results indicated dogs learned to inhibit their approach to a deceptive static point when the reward was visible during choice. However, when information about the reward’s location was later hidden, dogs reverted to following the demonstrator’s static point

Why do adult dogs ‘play’?

Among the Carnivora, play behaviour is usually made up of motor patterns characteristic of predatory, agonistic and courtship behaviour. Domestic dogs are unusual in that play is routinely performed by adults, both socially, with conspecifics and with humans, and also asocially, with objects. This enhanced playfulness is commonly thought to be a side effect of paedomorphosis, the perpetuation of juvenile traits into adulthood, but here we suggest that the functions of the different types of play are sufficiently distinct that they are unlikely to have arisen through a single evolutionary mechanism. Solitary play with objects appears to be derived from predatory behaviour: preferred toys are those that can be dismembered, and a complex habituation-like feedback system inhibits play with objects that are resistant to alteration. Intraspecific social play is structurally different from interspecific play and may therefore be motivationally distinct and serve different goals; for example, dogs often compete over objects when playing with other dogs, but are usually more cooperative when the play partner is human. The majority of dogs do not seem to regard competitive games played with a human partner as “dominance” contests: rather, winning possession of objects during games appears to be simply rewarding. Play may be an important factor in sociality, since dogs are capable of extracting social information not only from games in which they participate, but also from games that they observe between third parties. We suggest that the domestic dog’s characteristic playfulness in social contexts is an adaptive trait, selected during domestication to facilitate both training for specific purposes, and the formation of emotionally-based bonds between dog and owner. Play frequency and form may therefore be an indicator of the quality of dog-owner relationships

Inhibitory control, but not prolonged object-related experience appears to affect physical problem-solving performance of pet dogs

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance

Data for: Tiger Salamanders’ (Ambystoma tigrinum) Response Retention and Usage of Visual Cues Following Brumation

Dataset exploring retention of information over brumation in salamanders

Domesticated Dogs’ (Canis familiaris) Response to Dishonest Human Points

Pointing is a conventional communicative gesture used by humans to direct others’ attention to an environmental feature. Several researchers have argued that pointing becomes so ingrained for humans from a young age that children often have difficulty interpreting the gesture in a novel way. Recent research suggests domestic dogs are also sensitive to human gestures (including points) and proficient in recognizing and acting on humans’ visual attention. We explored the role of pointing indogs’ choice behavior and whether dogs, like human children, have difficulty interpreting the gesture novelly. In Experiment 1, we explored whether dogs would differentially follow a static human point when it was administered by a familiar or unfamiliar individual and that individual indicated or failed to indicate the correct location of a food reward. The results indicated dogs chose the container specified by the demonstrators’ point in the honest and dishonest condition. Demonstrator familiarity did not alter performance. In Experiment 2, we compared dogs’ propensity to follow a static point versus other cues (momentary point, standing location) when the cue never indicated the correct location of a food reward, which was either visible or hidden during choice. The results suggested dogs did not inhibit their approach to a location indicated by a deceptive static point even when thelocation of a reward was visibly available during choice. However, dogs used a deceptive momentary point or standing location to locate food in both visible and hidden trials. In Experiment 3, we explored if dogs could overcome their tendency to follow a deceptive static point. These results indicated dogs learned to inhibit their approach to a deceptive static point when the reward was visible during choice. However, when information about the reward’s location was later hidden, dogs reverted to following the demonstrator’s static point