Journal of Comparative Psychology最新文献

The featured article by Sakurai and Tomonaga (2024) in this issue has set out to test to what extent dolphins can estimate relative differences between pairs of object numbers by echolocation. For this they used three consecutive experiments with multiple controls and compared their data statistically to existing data from visual experiments done on other species. Previous studies already indicate that dolphins can visually estimate relative numerosity (e.g., Jaakkola et al., 2005; Yaman et al., 2012). Therefore, the goal of the present study was to investigate the dolphin's capacity to apply Weber's law (quantity judgments are more accurate proportional to the quantities investigated) to two sets of object quantities under sonar evaluation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Understanding conspecifics' age classes is crucial for animals, facilitating adaptive behavioral responses to their social environment. This may include gathering and integrating information through multiple modalities. Using a cross-modal preferential-looking paradigm, we investigated whether dogs possess a cross-modal mental representation of conspecific age classes. In Experiment 1, dogs were presented with images of an adult dog and a puppy projected side by side on a wall while a vocalization of either an adult dog or a puppy was played back simultaneously. To test the effect of relative body size between adult dog and puppy images, two size conditions (natural size and same size) were employed for visual stimuli. We examined dogs' looking behavior in response to cross-modally matched versus mismatched stimuli. We predicted that if dogs have cross-modal representations of age classes, they would exhibit prolonged attention toward matched images compared to mismatched ones. In Experiment 2, we administered the same paradigm within an eye-tracking experiment to further improve the measurement quality of dogs' looking times. However, dogs' looking times in either experiment did not demonstrate significant differences based on the match or mismatch between image and vocalization. Instead, we observed a size effect, indicating dogs' increased attention toward larger adult dog images compared to smaller puppy images. Consequently, we found no evidence of cross-modal representation of age class in dogs. Nonetheless, we found increased looking time and pupil size upon hearing puppy vocalizations compared to adult vocalizations in Experiment 2, suggesting that dogs exhibited heightened arousal when hearing puppy whining. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Organisms are believed to attempt to maximize their net energy intake while foraging. The paradoxical choice task shows that they may instead prefer to obtain information rather than primary reward when the outcome is uncertain. That is, they prefer stimuli that consistently predict food or no food (informative option), to stimuli that inconsistently predict both food and no food in larger amounts (noninformative option). This task also seems to indicate that some species (like pigeons, Columba livia, and starlings, Sturnus vulgaris) are more prone to choose the informative option, while other species (like rats, Rattus norvegicus, and humans, Homo sapiens) tend to favor reward procurement through the noninformative option. There is empirical evidence for and against this view. However, an analysis of the literature suggests that species differences in paradoxical choice might be less pronounced than often believed. We argue that pigeons and rats are usually not tested under conditions that are motivationally equivalent for both species-in particular, the opportunities to track consistent stimulus-food pairings are less often met in the rat studies than in the pigeon studies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Serial pattern learning describes behavior in which a subject anticipates not only the time and effort needed for the next reinforcer but also the pattern of time and effort to reinforcers after the first. Chandel et al. (2021) found that pigeons left a progressive (increasing ratio) schedule earlier than would have been optimal. They argued that the pigeons anticipated the harder-to-obtain reinforcers beyond the next one. In the present experiments, pigeons were trained on a progressive schedule for which each reinforcer was successively easier to obtain. However, the initial choice was between a fixed ratio schedule (FR23) for which a reinforcer was easier to obtain than the first reinforcer on the improving progressive schedule (32 pecks). Delayed discounting theory suggests that the pigeons would prefer the FR23 because more immediate reinforcers should be preferred, whereas serial pattern learning suggests that the progressive schedule might be preferred because easier-to-obtain reinforcers would follow the initially harder 32 pecks. In Experiment 1, a preference for the fixed ratio schedule was not found, however, in Experiment 2, when the two alternatives were equated for the number of reinforcers that could be obtained on each trial, a significant preference for the improving progressive schedule was found. The results of Experiment 2 were consistent with the serial pattern learning hypothesis. The pigeons did not choose the more immediate reinforcer associated with fixed ratio alternative. Rather, they showed a preference for the improving progressive schedule for which later reinforcers would be easier to obtain. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Animals navigate complex environments that present both hazards and essential resources. The prioritization of perceptual information that is relevant to their next actions, such as accessing or avoiding different resources, poses a potential challenge to animals, one that can impact survival. While animals' attentional biases toward negatively valanced and threatening stimuli have been explored, parallel biases toward differently valued resources remain understudied. Here, we assessed whether three primate species (chimpanzees [Pan troglodytes], gorillas [Gorilla gorilla gorilla], and Japanese macaques [Macaca fuscata]) prioritized their attention to positively valued resources-preferred foods compared to unpreferred foods. We employed a computerized dot probe attentional bias task in which we presented participants with paired images of their preferred and unpreferred foods in randomized locations (left or right). Latencies to touch the "probe" that replaced either image revealed that all three species responded faster to the probe when it replaced the preferred option (χ²(1) = 284.50, SE² = .03, p < .001). The uniformity of the primates' responses hints that a propensity to prioritize highly preferred items is rooted in these primates' evolutionary past, one that may serve as a mechanism to rapidly detect and locate resources such as highly valued foods. Future research will help disentangle the role that color plays in these biases. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Dogs are able to cooperate in reciprocal exchange with humans but little is known about the extent of these abilities (Range & Virányi, 2015). In the Still Face paradigm, infants reply to a sudden nonreciprocal facial expression with gaze aversion and an increase in re-engagement and distress behaviors (E. Tronick et al., 1978). We directly adapted this method; the dog's owner talked to the dog, then abruptly switched to a still, neutral face, maintaining eye contact. In Study 1 (N = 20), we found that dogs showed a significant decrease in the amount of looking at the owner in the Still Face phase, paralleling the results found in gaze aversion in infants, and they performed fewer pawing and vocalizations toward the person in the Still Face phase. In Study 2 (N = 60), we included one condition of continuous physical contact, and one condition that was a direct replication of the initial study without physical contact. Similar to human infants, we found a significant decrease in looking from the Interaction phase to the Still Face phase. However, in contrast to human infants, re-engagement and stress behaviors were higher in the Interaction phase than the Still Face phase. Looking and re-engagement behaviors differed based on the condition, with a smaller difference between phases in the Petting condition. These results suggest that dogs are capable of perceiving these small changes in human affect. However, unlike human infants, dogs seem to have greater expectations about physical interactions than verbal interactions, as they reacted more strongly to an Interaction phase without physical contact than the Still Face. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Animals can use asocial (e.g., environmental cues) or social (e.g., conspecific behavior) information when making decisions. We investigated decisions made by zebra finches when asocial and social sources conveyed agreeing or conflicting information, and assessed the influence of initial bias on decision making. Finches completed an initial preference test ranking preference for three colors of nest-building material. Birds in the agree group (n = 14) then observed demonstrators build nests using nonpreferred color material (social information) that matched the environment color (asocial information). Birds in the conflict group (n = 15) observed demonstrators build nests with nonpreferred color material that did not match the cage environment (another nonpreferred color). A final preference test assessed any changes in color preference. The agree group reduced average preference for their initially preferred color, but did not significantly increase average preference for the asocial/social colors. The conflict group also reduced average preference for the initially preferred color and also increased preference for the socially demonstrated color. Observers with stronger initial bias were less likely to choose the socially demonstrated color than observers with weaker initial bias. This shows that social information informs nest-building decisions, even when in conflict with asocial information. However, bias influences social information use and adds nuance to how different individuals use information when making decisions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

This article discusses the ephemeral reward task and how it is not always a clear and concise choice. This is demonstrated through some animal studies involving birds and primates. This article also shows that when compared to human studies, that there are positive correlations between the BART and optimal choice in the ephemeral reward task, meaning that those who took more risks also were more inclined to be optimal. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Delay of gratification and inhibitory control are generally considered measures of self-control. In humans, individual differences in measures of self-control are associated with a host of behavioral, neurological, cognitive, and health-related outcomes. Self-control is not unique to humans and has been demonstrated in a variety of nonhuman species using a variety of paradigms. In this study, the effect of sex and age on delay of gratification performance, as measured by the hybrid delay task, was tested in a sample of 88 chimpanzees. Additionally, whether individual differences in hybrid delay task performance were associated with different aspects of personality was examined in this study. Contrary to reports in human subjects, geriatric male chimpanzees were found to perform more efficiently than adult males, while no age differences were found between geriatric and adult females. Indeed, delay of gratification efficiency was positively associated with age in males and negatively associated with age in females. Chimpanzees that performed more efficiently on the hybrid delay task were also found to be rated as more intelligent, more extraverted, and less impulsive. These findings suggest that objective measures of efficiency in delay of gratification tasks are associated with different dimensions of personality, which have some overlapping construct validity. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A growing body of research demonstrates that humans can accurately perceive the emotional states of animals solely by listening to their calls, highlighting shared evolutionary ancestry. Yet, the cognitive and perceptual mechanisms underlying heterospecific emotion perception have remained open to investigation. One hypothesis is that humans rely on simple acoustic heuristics to make such judgments, for example, perceiving higher-pitched calls as reflecting heightened emotional arousal (the "pitch rule"). This could lead to accurate judgments of emotion since in most mammals, as in humans, vocal fundamental frequency (the acoustic determinant of the pitch percept) does objectively correlate with emotional arousal. In the present study, we used digital pitch manipulation to create pairs of animal calls that were perceptually identical except for pitch, and we measured human perceptions of the caller's emotional arousal using an online survey. Calls of six phylogenetically diverse species were included as stimuli. Participants attributed slightly but statistically significantly higher arousal to higher-pitched versions of the same calls. Variation in application of the pitch rule across species was not well explained by familiarity, and prior experience with cats did not significantly predict sensitivity to pitch in cat vocalizations. Cross-species variation also did not align with phylogenetic distance from humans, or the hypothetical usefulness of pitch for making accurate judgments. Thus, the pitch rule may be a "mammalomorphic" heuristic leading to accurate emotion judgments in some taxa and call types and erroneous judgments in others, depending in part on phylogenetic distance and the mechanisms of call production. (PsycInfo Database Record (c) 2024 APA, all rights reserved).