Domestic dogs (Canis familiaris) are sensitive to the attentional state of humans.

Twelve domestic dogs (Canis familiaris) were given a series of trials in which they were forbidden to take a piece of visible food. In some trials, the human continued to look at the dog throughout the trial (control condition), whereas in others, the human (a) left the room, (b) turned her back, (c) engaged in a distracting activity, or (d) closed her eyes. Dogs behaved in clearly different ways in most of the conditions in which the human did not watch them compared with the control condition, in which she did. In particular, when the human looked at them, dogs retrieved less food, approached it in a more indirect way, and sat (as opposed to laid down) more often than in the other conditions. Results are discussed in terms of domestic dogs' social-cognitive skills and their unique evolutionary and ontogenetic histories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incentive contrast in domestic dogs (Canis familiaris).

Dogs (Canis familiaris) trained to receive a preferred food (dry beef liver) from an experimenter learned to maintain a longer gaze on the experimenter than dogs receiving a less preferred food (dog pellets). Dogs downshifted from dry liver to pellets rejected food more frequently than nonshifted controls. Gaze duration also decreased in downshifted dogs below the level of a group always reinforced with pellets. In addition, downshifted dogs tended to move away from the experimenter, adopting a lying down posture. This phenomenon, called successive negative contrast, has been described in analogous experiments with a variety of mammalian species, but has failed to occur in similar experiments with nonmammalian vertebrates. Unlike similar previous observations, the present data were obtained in an environment involving interspecific communication. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preference for copying unambiguous demonstrations in dogs (Canis familiaris).

In an earlier study (P. Pongrácz et al., 2001), it was shown that human demonstration significantly enhances the detouring ability of dogs (Canis familiaris) around a V-shaped fence. The authors investigated the effect of the direction of the demonstrated detour and the dogs' detouring experience. They found that dogs' trial-and-error experience influences strongly the direction of the dogs' detours later, even if the demonstrator showed detours along the opposite side of the fence. However, dogs' preferences based on their own experiences were changed when the dogs observed demonstrations only on 1 side of the fence. Dogs with no trial-and-error experience followed the direction of 1-sided demonstrations. The change from dogs' own directions to the demonstrated directions seems not to be due to simple facilitative effects of social experience; the similarity with the demonstrated action depends on complex interactions between individual experience and socially provided information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Landmark-based search memory in the domestic dog (Canis familiaris).

Recent studies have suggested that any animal that relies on landmark-based search memory encodes and uses metric properties of space to navigate. So far, however, metric information provided by landmarks has been predominantly investigated in avian species. In the present study, I investigated whether the domestic dog (Canis familiaris), a mammalian species, encodes the distance and direction from landmarks. Dogs were trained to find a ball hidden next to an array of two distinct landmarks that remained at a constant location in a room from trial to trial. After training, the dogs were occasionally tested on unrewarded conditions where the array was either left in its usual position or shifted laterally, perpendicularly, or diagonally relative to the rear wall of the room. Although the dogs significantly shifted their search as a function of the displacement of the landmarks, they did not search at the predicted coordinates of the goal relative to the shift of the landmarks, suggesting that the global cues available in the testing room were also encoded and used by dogs to locate the position of the goal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-dependent decisions in dogs (Canis familiaris).

Investigated whether the foraging decisions of dogs (Canis familiaris) were time dependent and consistent with a temporal weighting rule (TWR) for maximizing the reliability of information. Dogs were given information about patches whose qualities varied over time. To stimulate natural conditions, interruptions at selected points in foraging were interposed. Patch choices were time dependent and closely matched the predictions of the TWR. Dogs relied on very recent information when available, but with increasing delays they used patch averages. The TWR may be a general solution to problems faced by foragers in variable environments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attachment behavior of adult dogs (Canis familiaris) living at rescue centers: Forming new bonds.

In this study, 60 shelter dogs (Canis familiaris) were observed in the modified version of the Strange Situation Test, which has proved to be a useful method for studying dogs' attachment behavior toward humans (J. Topàl, à. Miklòsi, V. Csònyi, & A. Dòka, 1998). Before testing, 40 dogs were handled 3 times for 10 min. In the test, handled dogs encountered 2 persons: the handler in the role of the owner(OW) and an unfamiliar person (UP), whereas the 20 nonhandled dogs encountered unfamiliar persons in both roles. Dogs in the handled group exhibited more contact seeking with the entering OW, less physical contact with the UP, less frequent following of the leaving UP, and less standing by the door in the presence of the OW. The specific response of the handled dogs toward the handler fulfilled the operational criteria of attachment. In shelter conditions, the remarkable demand for social contact with humans may result in rather fast forming of attachment even in adult dogs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dogs' ( Canis familaris ) responsiveness to human pointing gestures.

In a series of 3 experiments, dogs (Canisfamiliaris) were presented with variations of the human pointing gesture; gestures with reversed direction of movement, cross-pointing, and different arm extensions. Dogs performed at above chance level if they could see the hand (and index finger) protruding from the human body contour. If these minimum requirements were not accessible, dogs still could rely on the body position of the signaler. The direction of movement of the pointing arm did not influence the performance. In summary, these observations suggest that dogs are able to rely on relatively novel gestural forms of the human communicative pointing gesture and that they are able to comprehend to some extent the referential nature of human pointing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial memory in dogs (Canis familiaris) on a radial maze.

Working spatial memory in dogs (Canis familiaris) was tested in Experiments 1 and 2 on an 8-arm radial maze. When dogs chose freely among all 8 arms containing food in Experiment 1, they learned to enter all 8 arms with progressively fewer arm visits over trials. In Experiment 2, 2 groups of dogs were forced to visit 4 randomly chosen arms on the maze and then tested for memory of these arm visits using a win-shift rule for 1 group and a win-stay rule for the other group. Dogs performed better with the win-shift rule than with the win-stay rule. In Experiment 3, reference memory was investigated by using a 4-arm maze on which 0, 1, 3, and 6 pieces of food were consistently placed on different arms. Dogs learned to visit the arms with the larger amounts before the arms with the smaller amounts. Dogs’ memory capacity in these studies was found to be surprisingly low. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do dogs (Canis familiaris) seek help in an emergency?

The question of whether dogs recognize an emergency and understand the need to seek help from a bystander was tested in two experiments. In the first experiment, dogs' owners feigned a heart attack in an open field, and in the second experiment, dogs' owners experienced an accident in which a bookcase fell on them and pinned them to the floor. In these experiments, one or two bystanders were available to which dogs could go for help. The dogs' behavior was taped for 6 min after the owner had fallen and was later scored for the frequency and time the dogs spent performing different behaviors. In no case did a dog solicit help from a bystander. It is concluded that dogs did not understand the nature of the emergency or the need to obtain help. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Domestic dogs (Canis familiaris) use human gestures but not nonhuman tokens to find hidden food.

The authors examined the ability of domestic dogs to use human body cues (gestures) and equivalent-sized nonhuman cues to find hidden food in an object choice paradigm. In Experiment 1 the authors addressed the importance of the human element of the cue, and the effects of size, topography, and familiarity on dogs' success in using cues. Experiment 2 further explored the role of the human as cue-giver, and the impact of a change in the experimenter's attentional state during cue presentation. This included a systematic test of the role inanimate tokens play as cues apart from human placement. Our results indicate that dogs are more sensitive to human cues than equivalent nonhuman cues, and that the size of the cue is a critical element in determining dogs' success in following it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial encoding of hidden objects in dogs (Canis familiaris).

The authors investigated the type of spatial information that controls domestic dogs' (Canis familiaris) search behavior in a situation in which they have to locate a spatial position where they saw an object move and disappear. In Experiments 1 and 2, the authors manipulated all local and global sources of allocentric spatial information surrounding the hiding location. The results revealed that dogs relied on an egocentric frame of reference. Experiment 3 showed that dogs also encoded allocentric information when egocentric information was irrelevant. The authors conclude that dogs simultaneously encode both egocentric and allocentric spatial information to locate a spatial position, but they primarily base their search behavior on an egocentric frame of reference. The authors discuss under which natural conditions dogs might use these 2 sources of spatial information and detail the nature of spatial egocentric information and the circumstances underlying its use by dogs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of directed gaze in rhesus monkeys (Macaca mulatta).

To examine the ability of monkeys to detect the direction of attention of other individuals, the authors quantitatively investigated the visual scanning pattern of rhesus monkeys (Macaca mulatta) in response to visually presented images of a human frontal face. The present results demonstrated not only that monkeys predominantly gaze at the eyes as compared with other facial areas in terms of duration and number of fixations, but also that they gaze at the eyes for a longer time period and more frequently when a human face, presented as a stimulus, gazed at them than when the gaze was shifted. These results indicate that rhesus monkeys are sensitive to the directed gaze of humans, suggesting that monkeys pay more attention to the human whose attention is directed to them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dogs (Canis familiaris) learn their owners via observation in a manipulation task.

Eighty-seven pet dogs (Canis familiaris) were involved in an experiment in which they had to solve a task to obtain a ball. After witnessing a full demonstration by their owner (10 times pushing the handle of the box, which released a ball), most dogs preferred to touch the handle sooner and more frequently in comparison with other parts of the box, and they used the handle to get the ball. In contrast dogs in 3 control groups developed their own respective methods. The lack of emergence of the ball and playing after the demonstration did not affect the learning performance strongly. This suggests that in dogs the outcome of a demonstration plays only a restricted role in the manifestation of social learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Comparative Study of the Use of Visual Communicative Signals in Interactions Between Dogs (Canis familiaris) and Humans and Cats (Felis catus) and Humans.

Dogs' (Canis familiaris) and cats' (Felis catus) interspecific communicative behavior toward humans was investigated. In Experiment 1, the ability of dogs and cats to use human pointing gestures in an object-choice task was compared using 4 types of pointing cues differing in distance between the signaled object and the end of the fingertip and in visibility duration of the given signal. Using these gestures, both dogs and cats were able to find the hidden food; there was no significant difference in their performance. In Experiment 2, the hidden food was made inaccessible to the subjects to determine whether they could indicate the place of the hidden food to a naive owner. Cats lacked some components of attention-getting behavior compared with dogs. The results suggest that individual familiarization with pointing gestures ensures high-level performance in the presence of such gestures; however, species-specific differences could cause differences in signaling toward the human. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial memory of domestic dogs (Canis familiaris) for hidden objects in a detour task.

Spatial memory of domestic dogs (Canis familiaris) for hidden objects was investigated via a visible displacement problem of object permanence with a detour paradigm. Experiment 1 showed that dogs were able to spontaneously locate a disappearing object in a detour situation. In Experiments 2 and 3, dead reckoning and allocentric spatial information were put in conflict. Results revealed that dogs simultaneously encoded both sources of information when they had to bypass an obstacle to locate a hidden object. Experiment 3 also revealed that, over the course of testing, dogs gradually learned to rely predominantly on allocentric cues when the detour involved several reorientations. The current study reveals that spatial memory of dogs for hidden objects in a detour task was guided by flexibility in processing spatial information. Dogs could simultaneously encode dead reckoning and allocentric information to locate a disappearing object and used them hierarchically according to the complexity of the detour they encountered in the environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new perspective on barking in dogs (Canis familaris.).

The disparity in bark frequency and context between dogs (Canis familiaris) and wolves (Canis lupus) has led some researchers to conclude that barking in the domestic dog is nonfunctional. This conclusion attributes the differences primarily to genetic variation caused by domestication rather than to the influence of social environment on ontogeny. Other researchers, however, have concluded that vocal usage and response to vocalizations in mammals are strongly guided by social interactions. Closer evaluation of dog vocalizations with respect to social environment reveals developmental factors that lead to both frequent barking and barking in many contexts. Additionally, spectrographic analysis indicates that bark structure varies predictably with context, suggesting that barks can be divided into contextual subtypes and may be a more complex form of communication than given credit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visuospatial impairments in aged canines (Canis familiaris): The role of cognitive-behavioral flexibility.

This study used a novel delayed nonmatching-to-position task to compare visuospatial learning and memory in young and aged beagle dogs (Canis familiaris). The task used 3, rather than 2, spatial locations, which markedly increased difficulty. There were striking age differences in acquisition. Most of the aged canines did not learn the task, and those that did showed impaired learning when compared with the young canines. The aged canines also showed reduced maximal working memory capacity compared with the young canines. Analysis of the response patterns of individual canines indicated that the deficits were related to the use of ineffective strategies and inflexibility in strategy modification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-sectional study of object permanence in domestic puppies (Canis familiaris).

Visual accommodation and object permanence tests were administered to 70 puppies (Canis familiaris), aged 4 wks to 9 mo. The results showed that understanding of visible displacement problems emerged at the 5th wk and developed rapidly until the 8th wk. Although the search behaviors of older puppies were more flexible, no further significant development was observed between 8 wks and 9 mo. The results on invisible displacement tests suggest that understanding of invisible displacement problems appears around the 1st year in dogs' development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The magic cup: Great apes and domestic dogs (Canis familiaris) individuate objects according to their properties.

Despite current interest in dog (Canis familiaris) cognition, very little is known about how dogs represent objects and how they compare with other species, such as the great apes. Therefore, we investigated how dogs and great apes (chimpanzees [Pan troglodytes], bonobos [Pan paniscus], orangutans [Pongo pygmaeus], gorillas [Gorilla gorilla]) individuate objects in a classical violation of expectation paradigm. We used a container (magic cup) with a double bottom that allowed us to change the type of food that subjects had seen being placed in the container. Using a 2 × 2 design, we varied whether subjects received a generally preferred food and whether the food was substituted (surprise trials) or not (baseline trials). Apes showed increased begging and looking behaviors and dogs showed increased smelling behavior. Both species stayed near the experimenter more frequently in the surprise trials compared with baseline trials. Both species reacted to positive (i.e., good food substituted for bad food) and negative (i.e., bad food substituted for good food) surprises. These results suggest that apes and dogs were able to individuate objects according to their properties or type in comparable ways. In addition, we looked for frustration and elation effects, but subjects' behaviors were not influenced by the food they saw and which they received in previous trials. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Distinguishing logic from association in the solution of an invisible displacement task by children (Homo sapiens) and dogs (Canis familiaris): Using negation of disjunction.

Prior research on the ability to solve the Piagetian invisible displacement task has focused on prerequisite representational capacity. This study examines the additional prerequisite of deduction. As in other tasks (e.g., conservation and transitivity), it is difficult to distinguish between behavior that reflects logical inference from behavior that reflects associative generalization. Using the role of negation in logic whereby negative feedback about one belief increases the certainty of another (e.g., a disjunctive syllogism), task-naive dogs (Canis familiaris; n?=?19) and 4- to 6-year-old children (Homo sapiens; n?=?24) were given a task wherein a desirable object was shown to have disappeared from a container after it had passed behind 3 separate screens. As predicted, children (as per logic of negated disjunction) tended to increase their speed of checking the 3rd screen after failing to find the object behind the first 2 screens, whereas dogs (as per associative extinction) tended to significantly decrease their speed of checking the 3rd screen after failing to find the object behind the first 2 screens. (PsycINFO Database Record (c) 2010 APA, all rights reserved)